diff --git a/src/main/java/eu/siacs/conversations/persistance/FileBackend.java b/src/main/java/eu/siacs/conversations/persistance/FileBackend.java
index 2d5496f2f..8519e5dbd 100644
--- a/src/main/java/eu/siacs/conversations/persistance/FileBackend.java
+++ b/src/main/java/eu/siacs/conversations/persistance/FileBackend.java
@@ -1602,7 +1602,6 @@ public class FileBackend {
         return getVideoDimensions(metadataRetriever);
     }
 
-    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
     private Dimensions getPdfDocumentDimensions(final File file) {
         final ParcelFileDescriptor fileDescriptor;
         try {
@@ -1610,7 +1609,7 @@ public class FileBackend {
             if (fileDescriptor == null) {
                 return new Dimensions(0, 0);
             }
-        } catch (FileNotFoundException e) {
+        } catch (final FileNotFoundException e) {
             return new Dimensions(0, 0);
         }
         try {
@@ -1621,7 +1620,7 @@ public class FileBackend {
             page.close();
             pdfRenderer.close();
             return scalePdfDimensions(new Dimensions(height, width));
-        } catch (IOException | SecurityException e) {
+        } catch (final IOException | SecurityException e) {
             Log.d(Config.LOGTAG, "unable to get dimensions for pdf document", e);
             return new Dimensions(0, 0);
         }
diff --git a/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java b/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
index e73fdb23c..302fbf81d 100644
--- a/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
+++ b/src/main/java/eu/siacs/conversations/ui/RtpSessionActivity.java
@@ -521,6 +521,9 @@ public class RtpSessionActivity extends XmppActivity
             @StringRes int res;
             final String firstDenied =
                     getFirstDenied(permissionResult.grantResults, permissionResult.permissions);
+            if (firstDenied == null) {
+                return;
+            }
             if (Manifest.permission.RECORD_AUDIO.equals(firstDenied)) {
                 res = R.string.no_microphone_permission;
             } else if (Manifest.permission.CAMERA.equals(firstDenied)) {