diff --git a/app/src/main/java/com/owncloud/android/operations/RefreshFolderOperation.java b/app/src/main/java/com/owncloud/android/operations/RefreshFolderOperation.java
index 916ec1331f..b765b83b83 100644
--- a/app/src/main/java/com/owncloud/android/operations/RefreshFolderOperation.java
+++ b/app/src/main/java/com/owncloud/android/operations/RefreshFolderOperation.java
@@ -517,14 +517,12 @@ public class RefreshFolderOperation extends RemoteOperation {
         // get current data about local contents of the folder to synchronize
         Map<String, OCFile> localFilesMap;
         E2EVersion e2EVersion;
-        if (object instanceof DecryptedFolderMetadataFileV1) {
+        if (object instanceof DecryptedFolderMetadataFileV1 metadataFileV1) {
             e2EVersion = E2EVersion.V1_2;
-            localFilesMap = prefillLocalFilesMap((DecryptedFolderMetadataFileV1) object,
-                                                 fileDataStorageManager.getFolderContent(mLocalFolder, false));
+            localFilesMap = prefillLocalFilesMap(metadataFileV1, fileDataStorageManager.getFolderContent(mLocalFolder, false));
         } else {
             e2EVersion = E2EVersion.V2_0;
-            localFilesMap = prefillLocalFilesMap((DecryptedFolderMetadataFile) object,
-                                                 fileDataStorageManager.getFolderContent(mLocalFolder, false));
+            localFilesMap = prefillLocalFilesMap(object, fileDataStorageManager.getFolderContent(mLocalFolder, false));
 
             // update counter
             if (object != null) {
@@ -574,7 +572,7 @@ public class RefreshFolderOperation extends RemoteOperation {
                 updateFileNameForEncryptedFileV1(fileDataStorageManager,
                                                  (DecryptedFolderMetadataFileV1) object,
                                                  updatedFile);
-            } else {
+            } else if (object != null) {
                 updateFileNameForEncryptedFile(fileDataStorageManager,
                                                (DecryptedFolderMetadataFile) object,
                                                updatedFile);
diff --git a/app/src/main/java/com/owncloud/android/operations/UploadFileOperation.java b/app/src/main/java/com/owncloud/android/operations/UploadFileOperation.java
index bfebce4f12..521c8f95ec 100644
--- a/app/src/main/java/com/owncloud/android/operations/UploadFileOperation.java
+++ b/app/src/main/java/com/owncloud/android/operations/UploadFileOperation.java
@@ -436,7 +436,7 @@ public class UploadFileOperation extends SyncOperation {
         // parent file is not null anymore:
         // - it was created on fresh upload or
         // - resume of encrypted upload, then parent file exists already as unlock is only for direct parent
-
+        assert(parent != null);
         mFile.setParentId(parent.getFileId());
 
         // check if any parent is encrypted
diff --git a/scripts/analysis/lint-results.txt b/scripts/analysis/lint-results.txt
index 9027c31641..8bfb3e9e65 100644
--- a/scripts/analysis/lint-results.txt
+++ b/scripts/analysis/lint-results.txt
@@ -1,2 +1,2 @@
 DO NOT TOUCH; GENERATED BY DRONE
-      <span class="mdl-layout-title">Lint Report: 11 errors and 54 warnings</span>
+      <span class="mdl-layout-title">Lint Report: 11 errors and 51 warnings</span>