diff --git a/src/main/java/com/owncloud/android/datamodel/ThumbnailsCacheManager.java b/src/main/java/com/owncloud/android/datamodel/ThumbnailsCacheManager.java
index 7ed0a3a8bd8c..507e10f56b5d 100644
--- a/src/main/java/com/owncloud/android/datamodel/ThumbnailsCacheManager.java
+++ b/src/main/java/com/owncloud/android/datamodel/ThumbnailsCacheManager.java
@@ -43,6 +43,7 @@
 import com.owncloud.android.lib.common.OwnCloudAccount;
 import com.owncloud.android.lib.common.OwnCloudClient;
 import com.owncloud.android.lib.common.OwnCloudClientManagerFactory;
+import com.owncloud.android.lib.common.operations.RemoteOperation;
 import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 import com.owncloud.android.ui.adapter.DiskLruImageCache;
@@ -352,6 +353,10 @@ private Bitmap doOCFileInBackground() {
                                 getMethod = new GetMethod(uri);
                                 getMethod.setRequestHeader("Cookie",
                                         "nc_sameSiteCookielax=true;nc_sameSiteCookiestrict=true");
+
+                                getMethod.setRequestHeader(RemoteOperation.OCS_API_HEADER,
+                                        RemoteOperation.OCS_API_HEADER_VALUE);
+
                                 int status = mClient.executeMethod(getMethod);
                                 if (status == HttpStatus.SC_OK) {
                                     InputStream inputStream = getMethod.getResponseBodyAsStream();
diff --git a/src/main/java/com/owncloud/android/ui/adapter/ActivityListAdapter.java b/src/main/java/com/owncloud/android/ui/adapter/ActivityListAdapter.java
index f1caabbbef9c..cea515475b18 100644
--- a/src/main/java/com/owncloud/android/ui/adapter/ActivityListAdapter.java
+++ b/src/main/java/com/owncloud/android/ui/adapter/ActivityListAdapter.java
@@ -75,8 +75,8 @@
 
 public class ActivityListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
 
-    public static final int HEADER_TYPE = 100;
-    public static final int ACTIVITY_TYPE = 101;
+    private static final int HEADER_TYPE = 100;
+    private static final int ACTIVITY_TYPE = 101;
     private final ActivityListInterface activityListInterface;
     private final int px;
     private static final String TAG = ActivityListAdapter.class.getSimpleName();
@@ -101,7 +101,7 @@ public void setActivityItems(List<Object> activityItems, OwnCloudClient client)
         String sTime = "";
         for (Object o : activityItems) {
             Activity activity = (Activity) o;
-            String time = null;
+            String time;
             if (activity.getDatetime() != null) {
                 time = DisplayUtils.getRelativeTimestamp(context,
                         activity.getDatetime().getTime()).toString();
@@ -182,18 +182,15 @@ public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
                 activityViewHolder.list.setVisibility(View.VISIBLE);
                 activityViewHolder.list.removeAllViews();
 
-                activityViewHolder.list.post(new Runnable() {
-                    @Override
-                    public void run() {
-                        int w = activityViewHolder.list.getMeasuredWidth();
-                        int elPxSize = px + 20;
-                        int totalColumnCount = (int) Math.floor(w / elPxSize);
-
-                        try {
-                            activityViewHolder.list.setColumnCount(totalColumnCount);
-                        } catch (IllegalArgumentException e) {
-                            Log_OC.e(TAG, "error setting column count to " + totalColumnCount);
-                        }
+                activityViewHolder.list.post(() -> {
+                    int w = activityViewHolder.list.getMeasuredWidth();
+                    int elPxSize = px + 20;
+                    int totalColumnCount = (int) Math.floor(w / elPxSize);
+
+                    try {
+                        activityViewHolder.list.setColumnCount(totalColumnCount);
+                    } catch (IllegalArgumentException e) {
+                        Log_OC.e(TAG, "error setting column count to " + totalColumnCount);
                     }
                 });
 
@@ -231,12 +228,7 @@ private ImageView createThumbnail(final RichObject richObject) {
         params.setMargins(10, 10, 10, 10);
         ImageView imageView = new ImageView(context);
         imageView.setLayoutParams(params);
-        imageView.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                activityListInterface.onActivityClicked(richObject);
-            }
-        });
+        imageView.setOnClickListener(v -> activityListInterface.onActivityClicked(richObject));
         setBitmap(file, imageView);
 
         return imageView;
@@ -246,11 +238,19 @@ private void setBitmap(OCFile file, ImageView fileIcon) {
         // No Folder
         if (!file.isFolder()) {
             if ((MimeTypeUtil.isImage(file) || MimeTypeUtil.isVideo(file))) {
-                String uri = mClient.getBaseUri() + "" +
-                        "/index.php/apps/files/api/v1/thumbnail/" +
-                        px + "/" + px + Uri.encode(file.getRemotePath(), "/");
+                int placeholder;
 
-                Glide.with(context).using(new CustomGlideStreamLoader()).load(uri).into(fileIcon); //Using custom fetcher
+                if (MimeTypeUtil.isImage(file)) {
+                    placeholder = R.drawable.file_image;
+                } else {
+                    placeholder = R.drawable.file_movie;
+                }
+
+                String uri = mClient.getBaseUri() + "/index.php/apps/files/api/v1/thumbnail/" + px + "/" + px +
+                        Uri.encode(file.getRemotePath(), "/");
+
+                Glide.with(context).using(new CustomGlideStreamLoader()).load(uri).placeholder(placeholder)
+                        .error(placeholder).into(fileIcon); // using custom fetcher
 
             } else {
                 fileIcon.setImageDrawable(MimeTypeUtil.getFileTypeIcon(file.getMimetype(), file.getFileName(), null));
@@ -258,11 +258,8 @@ private void setBitmap(OCFile file, ImageView fileIcon) {
         } else {
             // Folder
             fileIcon.setImageDrawable(
-                    MimeTypeUtil.getFolderTypeIcon(
-                            file.isSharedWithMe() || file.isSharedWithSharee(),
-                            file.isSharedViaLink()
-                    )
-            );
+                    MimeTypeUtil.getFolderTypeIcon(file.isSharedWithMe() || file.isSharedWithSharee(),
+                            file.isSharedViaLink()));
         }
     }
 
@@ -278,8 +275,7 @@ private void downloadIcon(String icon, ImageView itemViewType) {
                 .placeholder(R.drawable.ic_activity)
                 .error(R.drawable.ic_activity)
                 .animate(android.R.anim.fade_in)
-                .listener(new SvgSoftwareLayerSetter<Uri>());
-
+                .listener(new SvgSoftwareLayerSetter<>());
 
         Uri uri = Uri.parse(icon);
         requestBuilder
@@ -319,7 +315,7 @@ public void onClick(View widget) {
         return ssb;
     }
 
-    public RichObject searchObjectByName(ArrayList<RichObject> richObjectList, String name) {
+    private RichObject searchObjectByName(ArrayList<RichObject> richObjectList, String name) {
         for (RichObject richObject : richObjectList) {
             if (richObject.getTag().equalsIgnoreCase(name))
                 return richObject;
diff --git a/src/main/java/com/owncloud/android/utils/glide/HttpStreamFetcher.java b/src/main/java/com/owncloud/android/utils/glide/HttpStreamFetcher.java
index cb7dd6d18c5d..d86dd4d6c330 100644
--- a/src/main/java/com/owncloud/android/utils/glide/HttpStreamFetcher.java
+++ b/src/main/java/com/owncloud/android/utils/glide/HttpStreamFetcher.java
@@ -28,6 +28,7 @@
 import com.owncloud.android.lib.common.OwnCloudAccount;
 import com.owncloud.android.lib.common.OwnCloudClient;
 import com.owncloud.android.lib.common.OwnCloudClientManagerFactory;
+import com.owncloud.android.lib.common.operations.RemoteOperation;
 import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 
@@ -65,12 +66,11 @@ public InputStream loadData(Priority priority) throws Exception {
                 GetMethod get = null;
                 try {
                     get = new GetMethod(mURL);
-                    get.setRequestHeader("Cookie",
-                            "nc_sameSiteCookielax=true;nc_sameSiteCookiestrict=true");
+                    get.setRequestHeader("Cookie", "nc_sameSiteCookielax=true;nc_sameSiteCookiestrict=true");
+                    get.setRequestHeader(RemoteOperation.OCS_API_HEADER, RemoteOperation.OCS_API_HEADER_VALUE);
                     int status = mClient.executeMethod(get);
                     if (status == HttpStatus.SC_OK) {
-                        InputStream inputStream = get.getResponseBodyAsStream();
-                        return inputStream;
+                        return get.getResponseBodyAsStream();
                     } else {
                         mClient.exhaustResponse(get.getResponseBodyAsStream());
                     }