diff --git a/app/src/main/java/foundation/e/drive/operations/DownloadFileOperation.java b/app/src/main/java/foundation/e/drive/operations/DownloadFileOperation.java
index 9bc6a9661cee104d0fcbbacfafa3dade3ac91c8f..f2549c6da683cf2bfd287d4bbe1b2bd425397bc7 100644
--- a/app/src/main/java/foundation/e/drive/operations/DownloadFileOperation.java
+++ b/app/src/main/java/foundation/e/drive/operations/DownloadFileOperation.java
@@ -12,7 +12,9 @@ package foundation.e.drive.operations;
 import static com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode.FILE_NOT_FOUND;
 import static com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode.FORBIDDEN;
 import static com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode.INVALID_OVERWRITE;
+import static com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode.NO_NETWORK_CONNECTION;
 import static com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode.OK;
+import static com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode.WRONG_CONNECTION;
 
 import static java.nio.file.StandardCopyOption.REPLACE_EXISTING;
 
@@ -93,6 +95,9 @@ public class DownloadFileOperation extends RemoteOperation {
                 mustRestart = false;
             }
 
+        } else if (isNetworkDisconnected(downloadResult)) {
+            mustRestart = false;
+            resultCode = downloadResult.getCode();
         } else {
             Timber.d("Download failed: %s, %s", downloadResult.getCode(), downloadResult.getLogMessage());
             resultCode = RemoteOperationResult.ResultCode.UNKNOWN_ERROR;
@@ -116,6 +121,10 @@ public class DownloadFileOperation extends RemoteOperation {
         return new RemoteOperationResult(resultCode);
     }
 
+    private boolean isNetworkDisconnected(@NonNull final RemoteOperationResult result) {
+        RemoteOperationResult.ResultCode resultCode = result.getCode();
+        return resultCode == NO_NETWORK_CONNECTION || resultCode == WRONG_CONNECTION;
+    }
 
     private RemoteOperationResult.ResultCode onDownloadSuccess(String tmpTargetFolderPath) {
         final String tmpFilePath = tmpTargetFolderPath + remoteFile.getRemotePath();
diff --git a/app/src/main/java/foundation/e/drive/operations/UploadFileOperation.java b/app/src/main/java/foundation/e/drive/operations/UploadFileOperation.java
index 321df21a1afc1994eec641939d0cd671ab5eaaee..35484f2fec8befb4903dc35660eb229af26d3300 100644
--- a/app/src/main/java/foundation/e/drive/operations/UploadFileOperation.java
+++ b/app/src/main/java/foundation/e/drive/operations/UploadFileOperation.java
@@ -31,6 +31,8 @@ import com.owncloud.android.lib.resources.users.GetUserInfoRemoteOperation;
 import com.owncloud.android.lib.common.operations.RemoteOperationResult.ResultCode;
 import java.io.File;
 import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Set;
 
 import foundation.e.drive.database.DbHelper;
 import foundation.e.drive.models.SyncedFileState;
@@ -43,8 +45,10 @@ import timber.log.Timber;
  * High level Operation which upload a local file to a remote cloud storage
  */
 public class UploadFileOperation extends RemoteOperation {
-    private final static String TAG = UploadFileOperation.class.getSimpleName();
     public final static int FILE_SIZE_FLOOR_FOR_CHUNKED = 3072000; //3MB
+
+    private static final Set<ResultCode> handledFailureCodes = getHandledFailureCodes();
+
     private final Context context;
     private final SyncedFileState syncedState;
     private final Account account; // TODO Remove as soon as  nextcloud library move all Operation to NextcloudClient instead of OwncloudClient
@@ -109,14 +113,24 @@ public class UploadFileOperation extends RemoteOperation {
      * @return
      */
     private ResultCode onUploadFailure(final ResultCode uploadResult, final String fileName) {
-        if (uploadResult != ResultCode.CONFLICT
-                && uploadResult != ResultCode.QUOTA_EXCEEDED) {
+        if (!handledFailureCodes.contains(uploadResult)) {
             Timber.d("Upload for %s failed : %s", fileName, uploadResult);
             return ResultCode.UNKNOWN_ERROR;
         }
         return uploadResult;
     }
 
+    @NonNull
+    private static Set<ResultCode> getHandledFailureCodes() {
+        final Set<ResultCode> handledResultCodes = new HashSet<>();
+        handledResultCodes.add(ResultCode.CONFLICT);
+        handledResultCodes.add(ResultCode.QUOTA_EXCEEDED);
+        handledResultCodes.add(ResultCode.WRONG_CONNECTION);
+        handledResultCodes.add(ResultCode.NO_NETWORK_CONNECTION);
+
+        return handledResultCodes;
+    }
+
     /**
      * Check condition required to upload the file:
      * - the local file exist
diff --git a/app/src/main/java/foundation/e/drive/services/SynchronizationService.java b/app/src/main/java/foundation/e/drive/services/SynchronizationService.java
index 8218f5b26fe6f95c1c988a668f9495ce120e10a4..1c2bc934fada761d5c1554169a7469a6b1c363e5 100644
--- a/app/src/main/java/foundation/e/drive/services/SynchronizationService.java
+++ b/app/src/main/java/foundation/e/drive/services/SynchronizationService.java
@@ -224,7 +224,12 @@ public class SynchronizationService extends Service implements OnRemoteOperation
         }
     }
 
-    private void startWorker(Integer threadIndex){
+    private void startWorker(int threadIndex) {
+        if (!isNetworkAvailable()) {
+            syncRequestQueue.clear();
+            return;
+        }
+
         if (!canStart(threadIndex) || isPaused()) return;
 
         final SyncRequest request = this.syncRequestQueue.poll(); //return null if empty
@@ -267,16 +272,21 @@ public class SynchronizationService extends Service implements OnRemoteOperation
      * @return false if nogo
      */
     private boolean canStart(int threadIndex) {
-        final boolean meteredNetworkAllowed = CommonUtils.isMeteredNetworkAllowed(account);
         final SyncWrapper syncWrapper = startedSync.get(threadIndex);
+        return (syncWrapper == null || !syncWrapper.isRunning());
+    }
 
-        return (syncWrapper == null || !syncWrapper.isRunning())
-                && CommonUtils.haveNetworkConnection(getApplicationContext(), meteredNetworkAllowed);
+    private boolean isNetworkAvailable() {
+        final boolean meteredNetworkAllowed = CommonUtils.isMeteredNetworkAllowed(account);
+        return CommonUtils.haveNetworkConnection(getApplicationContext(), meteredNetworkAllowed);
     }
 
     @Override
     public void onRemoteOperationFinish(@NonNull RemoteOperation callerOperation, @NonNull RemoteOperationResult result) {
         Timber.i("onRemoteOperationFinish()");
+
+        boolean isNetworkDisconnected = false;
+
         if (callerOperation instanceof RemoveFileOperation && result.isSuccess()) {
             DbHelper
                 .manageSyncedFileStateDB(
@@ -326,6 +336,11 @@ public class SynchronizationService extends Service implements OnRemoteOperation
                     //Case specific to DownloadFileOperation
                     Timber.d("%s : Sync_conflict: File is already up to date", operationClassName);
                     break;
+                case NO_NETWORK_CONNECTION:
+                case WRONG_CONNECTION:
+                    isNetworkDisconnected = true;
+                    Timber.d("%s : network issue: %s", operationClassName, result.getCode());
+                    break;
             }
         }
 
@@ -339,6 +354,10 @@ public class SynchronizationService extends Service implements OnRemoteOperation
                 break;
             }
         }
+
+        if (isNetworkDisconnected) {
+            syncRequestQueue.clear();
+        }
     }
 
     private void updateFailureCounter(SyncRequest request, boolean success) {