diff --git a/app/src/main/java/com/todoroo/astrid/activity/ShareLinkActivity.kt b/app/src/main/java/com/todoroo/astrid/activity/ShareLinkActivity.kt
index 673465d20..c22c1bf42 100644
--- a/app/src/main/java/com/todoroo/astrid/activity/ShareLinkActivity.kt
+++ b/app/src/main/java/com/todoroo/astrid/activity/ShareLinkActivity.kt
@@ -93,7 +93,7 @@ class ShareLinkActivity : InjectingAppCompatActivity() {
                     ?: uri.lastPathSegment
         }
         val basename = Files.getNameWithoutExtension(filename!!)
-        return Lists.newArrayList(FileHelper.copyToUri(context, preferences.attachmentsDirectory, uri, basename))
+        return Lists.newArrayList(FileHelper.copyToUri(context, preferences.attachmentsDirectory!!, uri, basename))
     }
 
     private fun copyMultipleAttachments(intent: Intent): ArrayList<Uri> {
@@ -101,7 +101,7 @@ class ShareLinkActivity : InjectingAppCompatActivity() {
         val uris = intent.getParcelableArrayListExtra<Uri>(Intent.EXTRA_STREAM)
         if (uris != null) {
             for (uri in uris) {
-                result.add(FileHelper.copyToUri(context, preferences.attachmentsDirectory, uri))
+                result.add(FileHelper.copyToUri(context, preferences.attachmentsDirectory!!, uri))
             }
         }
         return result
diff --git a/app/src/main/java/com/todoroo/astrid/activity/TaskEditFragment.kt b/app/src/main/java/com/todoroo/astrid/activity/TaskEditFragment.kt
index e2fc623f7..542d15e2e 100755
--- a/app/src/main/java/com/todoroo/astrid/activity/TaskEditFragment.kt
+++ b/app/src/main/java/com/todoroo/astrid/activity/TaskEditFragment.kt
@@ -337,7 +337,7 @@ class TaskEditFragment : Fragment(), Toolbar.OnMenuItemClickListener {
         val model = editViewModel.task!!
         val userActivity = UserActivity()
         if (picture != null) {
-            val output = FileHelper.copyToUri(context, preferences.attachmentsDirectory, picture)
+            val output = FileHelper.copyToUri(context, preferences.attachmentsDirectory!!, picture)
             userActivity.setPicture(output)
         }
         userActivity.message = message
diff --git a/app/src/main/java/com/todoroo/astrid/files/FilesControlSet.kt b/app/src/main/java/com/todoroo/astrid/files/FilesControlSet.kt
index ab353ab00..51fa868e2 100644
--- a/app/src/main/java/com/todoroo/astrid/files/FilesControlSet.kt
+++ b/app/src/main/java/com/todoroo/astrid/files/FilesControlSet.kt
@@ -132,14 +132,14 @@ class FilesControlSet : TaskEditControlFragment() {
     }
 
     private fun copyToAttachmentDirectory(input: Uri?) {
-        newAttachment(FileHelper.copyToUri(context, preferences.attachmentsDirectory, input))
+        newAttachment(FileHelper.copyToUri(requireContext(), preferences.attachmentsDirectory!!, input!!))
     }
 
     private fun newAttachment(output: Uri) {
         val attachment = TaskAttachment(
                 viewModel.task!!.uuid,
                 output,
-                FileHelper.getFilename(context, output)!!)
+                FileHelper.getFilename(requireContext(), output)!!)
         lifecycleScope.launch {
             taskAttachmentDao.createNew(attachment)
             addAttachment(attachment)
diff --git a/app/src/main/java/org/tasks/backup/TasksJsonExporter.kt b/app/src/main/java/org/tasks/backup/TasksJsonExporter.kt
index 16c62b68a..18e742a0e 100755
--- a/app/src/main/java/org/tasks/backup/TasksJsonExporter.kt
+++ b/app/src/main/java/org/tasks/backup/TasksJsonExporter.kt
@@ -83,12 +83,12 @@ class TasksJsonExporter @Inject constructor(
                 doTasksExport(os, tasks)
                 os!!.close()
                 val externalStorageBackup = FileHelper.newFile(
-                        context,
-                        preferences.backupDirectory,
+                        context!!,
+                        preferences.backupDirectory!!,
                         MIME,
                         Files.getNameWithoutExtension(filename),
                         EXTENSION)
-                FileHelper.copyStream(context, internalStorageBackup, externalStorageBackup)
+                FileHelper.copyStream(context!!, internalStorageBackup, externalStorageBackup)
                 workManager.scheduleDriveUpload(externalStorageBackup, exportType == ExportType.EXPORT_TYPE_SERVICE)
                 BackupManager(context).dataChanged()
             }
diff --git a/app/src/main/java/org/tasks/drive/DriveInvoker.kt b/app/src/main/java/org/tasks/drive/DriveInvoker.kt
index 41a3c91cb..e3b1420b0 100644
--- a/app/src/main/java/org/tasks/drive/DriveInvoker.kt
+++ b/app/src/main/java/org/tasks/drive/DriveInvoker.kt
@@ -74,7 +74,7 @@ class DriveInvoker @Inject constructor(
 
     @Throws(IOException::class)
     suspend fun createFile(folderId: String, uri: Uri?) {
-        val mime = FileHelper.getMimeType(context, uri)
+        val mime = FileHelper.getMimeType(context, uri!!)
         val metadata = File()
                 .setParents(listOf(folderId))
                 .setMimeType(mime)
diff --git a/app/src/main/java/org/tasks/files/FileHelper.java b/app/src/main/java/org/tasks/files/FileHelper.java
deleted file mode 100644
index 0021ea502..000000000
--- a/app/src/main/java/org/tasks/files/FileHelper.java
+++ /dev/null
@@ -1,288 +0,0 @@
-package org.tasks.files;
-
-import static android.content.ContentResolver.SCHEME_CONTENT;
-import static android.provider.DocumentsContract.EXTRA_INITIAL_URI;
-import static androidx.core.content.FileProvider.getUriForFile;
-import static com.google.common.collect.Iterables.any;
-import static com.todoroo.astrid.utility.Constants.FILE_PROVIDER_AUTHORITY;
-import static org.tasks.Strings.isNullOrEmpty;
-
-import android.annotation.TargetApi;
-import android.app.Activity;
-import android.content.ContentResolver;
-import android.content.Context;
-import android.content.Intent;
-import android.content.pm.PackageManager;
-import android.database.Cursor;
-import android.net.Uri;
-import android.os.Build;
-import android.provider.OpenableColumns;
-import android.webkit.MimeTypeMap;
-import android.widget.Toast;
-import androidx.annotation.Nullable;
-import androidx.documentfile.provider.DocumentFile;
-import androidx.fragment.app.Fragment;
-import com.google.common.io.ByteStreams;
-import com.google.common.io.Files;
-import java.io.File;
-import java.io.FileNotFoundException;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.OutputStream;
-import java.util.Arrays;
-import java.util.List;
-import org.tasks.R;
-import timber.log.Timber;
-
-public class FileHelper {
-
-  public static final int MAX_FILENAME_LENGTH = 40;
-
-  public static Intent newFilePickerIntent(Activity activity, Uri initial, String... mimeTypes) {
-    Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT);
-    intent.putExtra("android.content.extra.SHOW_ADVANCED", true);
-    intent.putExtra("android.content.extra.FANCY", true);
-    intent.putExtra("android.content.extra.SHOW_FILESIZE", true);
-    intent.addCategory(Intent.CATEGORY_OPENABLE);
-    setInitialUri(activity, intent, initial);
-    if (mimeTypes.length == 1) {
-      intent.setType(mimeTypes[0]);
-    } else {
-      intent.setType("*/*");
-      if (mimeTypes.length > 1) {
-        intent.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes);
-      }
-    }
-    return intent;
-  }
-
-  public static void newDirectoryPicker(Fragment fragment, int rc, @Nullable Uri initial) {
-    Intent intent = new Intent(Intent.ACTION_OPEN_DOCUMENT_TREE);
-    intent.addFlags(
-        Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION
-            | Intent.FLAG_GRANT_WRITE_URI_PERMISSION
-            | Intent.FLAG_GRANT_READ_URI_PERMISSION
-            | Intent.FLAG_GRANT_PREFIX_URI_PERMISSION);
-    intent.putExtra("android.content.extra.SHOW_ADVANCED", true);
-    intent.putExtra("android.content.extra.FANCY", true);
-    intent.putExtra("android.content.extra.SHOW_FILESIZE", true);
-    setInitialUri(fragment.getContext(), intent, initial);
-    fragment.startActivityForResult(intent, rc);
-  }
-
-  @TargetApi(Build.VERSION_CODES.O)
-  private static void setInitialUri(Context context, Intent intent, Uri uri) {
-    if (uri == null || !uri.getScheme().equals(SCHEME_CONTENT)) {
-      return;
-    }
-
-    try {
-      intent.putExtra(EXTRA_INITIAL_URI, DocumentFile.fromTreeUri(context, uri).getUri());
-    } catch (Exception e) {
-      Timber.e(e);
-    }
-  }
-
-  public static void delete(Context context, Uri uri) {
-    if (uri == null) {
-      return;
-    }
-
-    switch (uri.getScheme()) {
-      case "content":
-        DocumentFile documentFile = DocumentFile.fromSingleUri(context, uri);
-        documentFile.delete();
-        break;
-      case "file":
-        delete(new File(uri.getPath()));
-        break;
-    }
-  }
-
-  private static void delete(File... files) {
-    if (files == null) {
-      return;
-    }
-
-    for (File file : files) {
-      if (file.isDirectory()) {
-        delete(file.listFiles());
-      } else {
-        file.delete();
-      }
-    }
-  }
-
-  public @Nullable static String getFilename(Context context, Uri uri) {
-    switch (uri.getScheme()) {
-      case ContentResolver.SCHEME_FILE:
-        return uri.getLastPathSegment();
-      case SCHEME_CONTENT:
-        Cursor cursor = context.getContentResolver().query(uri, null, null, null, null);
-        if (cursor != null && cursor.moveToFirst()) {
-          try {
-            return cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME));
-          } finally {
-            cursor.close();
-          }
-        }
-        break;
-    }
-    return null;
-  }
-
-  public static String getExtension(Context context, Uri uri) {
-    if (uri.getScheme().equals(ContentResolver.SCHEME_CONTENT)) {
-      String mimeType = context.getContentResolver().getType(uri);
-      String extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mimeType);
-      if (!isNullOrEmpty(extension)) {
-        return extension;
-      }
-    }
-
-    String extension = MimeTypeMap.getFileExtensionFromUrl(uri.getPath());
-    if (!isNullOrEmpty(extension)) {
-      return extension;
-    }
-
-    return Files.getFileExtension(getFilename(context, uri));
-  }
-
-  public static String getMimeType(Context context, Uri uri) {
-    String mimeType = context.getContentResolver().getType(uri);
-    if (!isNullOrEmpty(mimeType)) {
-      return mimeType;
-    }
-    String extension = getExtension(context, uri);
-    return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
-  }
-
-  public static void startActionView(Activity context, Uri uri) {
-    if (uri == null) {
-      return;
-    }
-
-    String mimeType = getMimeType(context, uri);
-    Intent intent = new Intent(Intent.ACTION_VIEW);
-    if (uri.getScheme().equals(SCHEME_CONTENT)) {
-      uri = copyToUri(context, Uri.fromFile(context.getExternalCacheDir()), uri);
-    }
-    Uri share = getUriForFile(context, FILE_PROVIDER_AUTHORITY, new File(uri.getPath()));
-    intent.setDataAndType(share, mimeType);
-    grantReadPermissions(intent);
-    PackageManager packageManager = context.getPackageManager();
-    if (intent.resolveActivity(packageManager) != null) {
-      context.startActivity(intent);
-    } else {
-      Toast.makeText(context, R.string.no_application_found, Toast.LENGTH_SHORT).show();
-    }
-  }
-
-  private static void grantReadPermissions(Intent intent) {
-    intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
-  }
-
-  public static Uri newFile(
-      Context context, Uri destination, String mimeType, String baseName, String extension)
-      throws IOException {
-    String filename = getNonCollidingFileName(context, destination, baseName, extension);
-    switch (destination.getScheme()) {
-      case "content":
-        DocumentFile tree = DocumentFile.fromTreeUri(context, destination);
-        DocumentFile f1 = tree.createFile(mimeType, filename);
-        if (f1 == null) {
-          throw new FileNotFoundException("Failed to create " + filename);
-        }
-        return f1.getUri();
-      case "file":
-        File dir = new File(destination.getPath());
-        if (!dir.exists() && !dir.mkdirs()) {
-          throw new IOException("Failed to create %s" + dir.getAbsolutePath());
-        }
-        File f2 = new File(dir.getAbsolutePath() + File.separator + filename);
-        if (f2.createNewFile()) {
-          return Uri.fromFile(f2);
-        }
-        throw new FileNotFoundException("Failed to create " + filename);
-      default:
-        throw new IllegalArgumentException("Unknown URI scheme: " + destination.getScheme());
-    }
-  }
-
-  public static Uri copyToUri(Context context, Uri destination, Uri input) {
-    String filename = getFilename(context, input);
-    return copyToUri(context, destination, input, Files.getNameWithoutExtension(filename));
-  }
-
-  public static Uri copyToUri(Context context, Uri destination, Uri input, String basename) {
-    try {
-      Uri output =
-          newFile(
-              context,
-              destination,
-              getMimeType(context, input),
-              basename,
-              getExtension(context, input));
-      copyStream(context, input, output);
-      return output;
-    } catch (IOException e) {
-      throw new IllegalStateException(e);
-    }
-  }
-
-  public static void copyStream(Context context, Uri input, Uri output) {
-    ContentResolver contentResolver = context.getContentResolver();
-    try {
-      InputStream inputStream = contentResolver.openInputStream(input);
-      OutputStream outputStream = contentResolver.openOutputStream(output);
-      ByteStreams.copy(inputStream, outputStream);
-      inputStream.close();
-      outputStream.close();
-    } catch (IOException e) {
-      throw new IllegalStateException(e);
-    }
-  }
-
-  private static String getNonCollidingFileName(
-      Context context, Uri uri, String baseName, String extension) {
-    int tries = 1;
-    if (!extension.startsWith(".")) {
-      extension = "." + extension;
-    }
-    String tempName = baseName;
-    switch (uri.getScheme()) {
-      case SCHEME_CONTENT:
-        DocumentFile dir = DocumentFile.fromTreeUri(context, uri);
-        List<DocumentFile> documentFiles = Arrays.asList(dir.listFiles());
-        while (true) {
-          String result = tempName + extension;
-          if (any(documentFiles, f -> f.getName().equals(result))) {
-            tempName = baseName + "-" + tries;
-            tries++;
-          } else {
-            break;
-          }
-        }
-        break;
-      case ContentResolver.SCHEME_FILE:
-        File f = new File(uri.getPath(), baseName + extension);
-        while (f.exists()) {
-          tempName = baseName + "-" + tries; // $NON-NLS-1$
-          f = new File(uri.getPath(), tempName + extension);
-          tries++;
-        }
-        break;
-    }
-    return tempName + extension;
-  }
-
-  public static String uri2String(@Nullable Uri uri) {
-    if (uri == null) {
-      return "";
-    }
-    if (uri.getScheme().equals(ContentResolver.SCHEME_FILE)) {
-      return new File(uri.getPath()).getAbsolutePath();
-    }
-    return uri.toString();
-  }
-}
diff --git a/app/src/main/java/org/tasks/files/FileHelper.kt b/app/src/main/java/org/tasks/files/FileHelper.kt
new file mode 100644
index 000000000..2262e22e0
--- /dev/null
+++ b/app/src/main/java/org/tasks/files/FileHelper.kt
@@ -0,0 +1,265 @@
+package org.tasks.files
+
+import android.annotation.TargetApi
+import android.app.Activity
+import android.content.ContentResolver
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import android.provider.DocumentsContract
+import android.provider.OpenableColumns
+import android.webkit.MimeTypeMap
+import android.widget.Toast
+import androidx.core.content.FileProvider
+import androidx.documentfile.provider.DocumentFile
+import androidx.fragment.app.Fragment
+import com.google.common.collect.Iterables
+import com.google.common.io.ByteStreams
+import com.google.common.io.Files
+import com.todoroo.astrid.utility.Constants
+import org.tasks.R
+import org.tasks.Strings.isNullOrEmpty
+import timber.log.Timber
+import java.io.File
+import java.io.FileNotFoundException
+import java.io.IOException
+import java.util.*
+
+object FileHelper {
+    const val MAX_FILENAME_LENGTH = 40
+    fun newFilePickerIntent(activity: Activity?, initial: Uri?, vararg mimeTypes: String?): Intent {
+        val intent = Intent(Intent.ACTION_OPEN_DOCUMENT)
+        intent.putExtra("android.content.extra.SHOW_ADVANCED", true)
+        intent.putExtra("android.content.extra.FANCY", true)
+        intent.putExtra("android.content.extra.SHOW_FILESIZE", true)
+        intent.addCategory(Intent.CATEGORY_OPENABLE)
+        setInitialUri(activity, intent, initial)
+        if (mimeTypes.size == 1) {
+            intent.type = mimeTypes[0]
+        } else {
+            intent.type = "*/*"
+            if (mimeTypes.size > 1) {
+                intent.putExtra(Intent.EXTRA_MIME_TYPES, mimeTypes)
+            }
+        }
+        return intent
+    }
+
+    fun newDirectoryPicker(fragment: Fragment, rc: Int, initial: Uri?) {
+        val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)
+        intent.addFlags(
+                Intent.FLAG_GRANT_PERSISTABLE_URI_PERMISSION
+                        or Intent.FLAG_GRANT_WRITE_URI_PERMISSION
+                        or Intent.FLAG_GRANT_READ_URI_PERMISSION
+                        or Intent.FLAG_GRANT_PREFIX_URI_PERMISSION)
+        intent.putExtra("android.content.extra.SHOW_ADVANCED", true)
+        intent.putExtra("android.content.extra.FANCY", true)
+        intent.putExtra("android.content.extra.SHOW_FILESIZE", true)
+        setInitialUri(fragment.context, intent, initial)
+        fragment.startActivityForResult(intent, rc)
+    }
+
+    @TargetApi(Build.VERSION_CODES.O)
+    private fun setInitialUri(context: Context?, intent: Intent, uri: Uri?) {
+        if (uri == null || uri.scheme != ContentResolver.SCHEME_CONTENT) {
+            return
+        }
+        try {
+            intent.putExtra(DocumentsContract.EXTRA_INITIAL_URI, DocumentFile.fromTreeUri(context!!, uri)!!.uri)
+        } catch (e: Exception) {
+            Timber.e(e)
+        }
+    }
+
+    fun delete(context: Context?, uri: Uri?) {
+        if (uri == null) {
+            return
+        }
+        when (uri.scheme) {
+            "content" -> {
+                val documentFile = DocumentFile.fromSingleUri(context!!, uri)
+                documentFile!!.delete()
+            }
+            "file" -> delete(File(uri.path))
+        }
+    }
+
+    private fun delete(vararg files: File) {
+        if (files == null) {
+            return
+        }
+        for (file in files) {
+            if (file.isDirectory) {
+                delete(*file.listFiles())
+            } else {
+                file.delete()
+            }
+        }
+    }
+
+    fun getFilename(context: Context, uri: Uri): String? {
+        when (uri.scheme) {
+            ContentResolver.SCHEME_FILE -> return uri.lastPathSegment
+            ContentResolver.SCHEME_CONTENT -> {
+                val cursor = context.contentResolver.query(uri, null, null, null, null)
+                if (cursor != null && cursor.moveToFirst()) {
+                    return try {
+                        cursor.getString(cursor.getColumnIndex(OpenableColumns.DISPLAY_NAME))
+                    } finally {
+                        cursor.close()
+                    }
+                }
+            }
+        }
+        return null
+    }
+
+    fun getExtension(context: Context, uri: Uri): String? {
+        if (uri.scheme == ContentResolver.SCHEME_CONTENT) {
+            val mimeType = context.contentResolver.getType(uri)
+            val extension = MimeTypeMap.getSingleton().getExtensionFromMimeType(mimeType)
+            if (!isNullOrEmpty(extension)) {
+                return extension
+            }
+        }
+        val extension = MimeTypeMap.getFileExtensionFromUrl(uri.path)
+        return if (!isNullOrEmpty(extension)) {
+            extension
+        } else Files.getFileExtension(getFilename(context, uri)!!)
+    }
+
+    fun getMimeType(context: Context, uri: Uri): String? {
+        val mimeType = context.contentResolver.getType(uri)
+        if (!isNullOrEmpty(mimeType)) {
+            return mimeType
+        }
+        val extension = getExtension(context, uri)
+        return MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension)
+    }
+
+    fun startActionView(context: Activity, uri: Uri?) {
+        var uri = uri ?: return
+        val mimeType = getMimeType(context, uri)
+        val intent = Intent(Intent.ACTION_VIEW)
+        if (uri.scheme == ContentResolver.SCHEME_CONTENT) {
+            uri = copyToUri(context, Uri.fromFile(context.externalCacheDir), uri)
+        }
+        val share = FileProvider.getUriForFile(context, Constants.FILE_PROVIDER_AUTHORITY, File(uri.path))
+        intent.setDataAndType(share, mimeType)
+        grantReadPermissions(intent)
+        val packageManager = context.packageManager
+        if (intent.resolveActivity(packageManager) != null) {
+            context.startActivity(intent)
+        } else {
+            Toast.makeText(context, R.string.no_application_found, Toast.LENGTH_SHORT).show()
+        }
+    }
+
+    private fun grantReadPermissions(intent: Intent) {
+        intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+    }
+
+    @JvmStatic
+    @Throws(IOException::class)
+    fun newFile(
+            context: Context, destination: Uri, mimeType: String?, baseName: String, extension: String?): Uri {
+        val filename = getNonCollidingFileName(context, destination, baseName, extension)
+        return when (destination.scheme) {
+            "content" -> {
+                val tree = DocumentFile.fromTreeUri(context, destination)
+                val f1 = tree!!.createFile(mimeType!!, filename)
+                        ?: throw FileNotFoundException("Failed to create $filename")
+                f1.uri
+            }
+            "file" -> {
+                val dir = File(destination.path)
+                if (!dir.exists() && !dir.mkdirs()) {
+                    throw IOException("Failed to create %s" + dir.absolutePath)
+                }
+                val f2 = File(dir.absolutePath + File.separator + filename)
+                if (f2.createNewFile()) {
+                    return Uri.fromFile(f2)
+                }
+                throw FileNotFoundException("Failed to create $filename")
+            }
+            else -> throw IllegalArgumentException("Unknown URI scheme: " + destination.scheme)
+        }
+    }
+
+    fun copyToUri(context: Context, destination: Uri, input: Uri): Uri {
+        val filename = getFilename(context, input)
+        return copyToUri(context, destination, input, Files.getNameWithoutExtension(filename!!))
+    }
+
+    fun copyToUri(context: Context, destination: Uri, input: Uri, basename: String): Uri {
+        return try {
+            val output = newFile(
+                    context,
+                    destination,
+                    getMimeType(context, input),
+                    basename,
+                    getExtension(context, input))
+            copyStream(context, input, output)
+            output
+        } catch (e: IOException) {
+            throw IllegalStateException(e)
+        }
+    }
+
+    fun copyStream(context: Context, input: Uri?, output: Uri?) {
+        val contentResolver = context.contentResolver
+        try {
+            val inputStream = contentResolver.openInputStream(input!!)
+            val outputStream = contentResolver.openOutputStream(output!!)
+            ByteStreams.copy(inputStream!!, outputStream!!)
+            inputStream.close()
+            outputStream.close()
+        } catch (e: IOException) {
+            throw IllegalStateException(e)
+        }
+    }
+
+    private fun getNonCollidingFileName(
+            context: Context, uri: Uri, baseName: String, extension: String?): String {
+        var extension = extension
+        var tries = 1
+        if (!extension!!.startsWith(".")) {
+            extension = ".$extension"
+        }
+        var tempName = baseName
+        when (uri.scheme) {
+            ContentResolver.SCHEME_CONTENT -> {
+                val dir = DocumentFile.fromTreeUri(context, uri)
+                val documentFiles = Arrays.asList(*dir!!.listFiles())
+                while (true) {
+                    val result = tempName + extension
+                    if (Iterables.any(documentFiles) { f: DocumentFile? -> f!!.name == result }) {
+                        tempName = "$baseName-$tries"
+                        tries++
+                    } else {
+                        break
+                    }
+                }
+            }
+            ContentResolver.SCHEME_FILE -> {
+                var f = File(uri.path, baseName + extension)
+                while (f.exists()) {
+                    tempName = "$baseName-$tries" // $NON-NLS-1$
+                    f = File(uri.path, tempName + extension)
+                    tries++
+                }
+            }
+        }
+        return tempName + extension
+    }
+
+    fun uri2String(uri: Uri?): String {
+        if (uri == null) {
+            return ""
+        }
+        return if (uri.scheme == ContentResolver.SCHEME_FILE) {
+            File(uri.path).absolutePath
+        } else uri.toString()
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/tasks/preferences/fragments/Backups.kt b/app/src/main/java/org/tasks/preferences/fragments/Backups.kt
index 0c8ac54d4..189eb31e2 100644
--- a/app/src/main/java/org/tasks/preferences/fragments/Backups.kt
+++ b/app/src/main/java/org/tasks/preferences/fragments/Backups.kt
@@ -162,7 +162,7 @@ class Backups : InjectingPreferenceFragment() {
         } else if (requestCode == REQUEST_PICKER) {
             if (resultCode == RESULT_OK) {
                 val uri = data!!.data
-                val extension = FileHelper.getExtension(activity, uri)
+                val extension = FileHelper.getExtension(requireContext(), uri!!)
                 if (!("json".equals(extension, ignoreCase = true) || "xml".equals(
                         extension,
                         ignoreCase = true