Try to takkle down export dir issues

src/main/java/de/dennisguse/opentracks/util/ExportUtils.java

@@ -6,6 +6,7 @@ import android.database.Cursor;
 import android.net.Uri;
 import android.provider.DocumentsContract;
 import android.util.Log;
+import android.widget.Toast;
 
 import androidx.documentfile.provider.DocumentFile;
 
@@ -17,6 +18,7 @@ import java.util.List;
 import java.util.UUID;
 import java.util.regex.Pattern;
 
+import de.dennisguse.opentracks.R;
 import de.dennisguse.opentracks.content.data.Track;
 import de.dennisguse.opentracks.io.file.TrackFileFormat;
 import de.dennisguse.opentracks.io.file.exporter.ExportService;
@@ -33,6 +35,11 @@ public class ExportUtils {
             TrackFileFormat trackFileFormat = PreferencesUtils.getExportTrackFileFormat();
             DocumentFile directory = PreferencesUtils.getDefaultExportDirectoryUri(context);
 
+            if (directory == null || !directory.canWrite()) {
+                Toast.makeText(context, R.string.export_cannot_write_to_dir, Toast.LENGTH_LONG).show();
+                return;
+            }
+
             ExportService.enqueue(context, resultReceiver, trackId, trackFileFormat, directory.getUri());
         }
     }

src/main/java/de/dennisguse/opentracks/util/IntentUtils.java

@@ -217,13 +217,10 @@ public class IntentUtils {
             return;
         }
         final Uri documentUri = documentFile.getUri();
-        final List<UriPermission> persistedUriPermissions = context.getContentResolver().getPersistedUriPermissions();
-        for (final UriPermission permission : persistedUriPermissions) {
-            final Uri uri = permission.getUri();
-            if (uri.equals(documentUri)) {
-                context.getContentResolver().releasePersistableUriPermission(uri, 0);
-            }
-        }
+        context.getContentResolver().getPersistedUriPermissions().stream()
+                .map(UriPermission::getUri)
+                .filter(documentUri::equals)
+                .forEach(u -> context.getContentResolver().releasePersistableUriPermission(u, 0));
     }
 
 }