diff --git a/app/build.gradle b/app/build.gradle
index f6fedaf4d..e420d607d 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -20,6 +20,10 @@ android {
             pseudoLocalesEnabled true
         }
     }
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_8
+        targetCompatibility JavaVersion.VERSION_1_8
+    }
 
     productFlavors {
         fdroid {
@@ -34,12 +38,12 @@ allprojects {
         maven { url "https://maven.google.com"}
     }
 }
-ext.supportLibraryVersion = '27.1.0'
+ext.supportLibraryVersion = '27.0.2'
 ext.glideLibraryVersion = '4.6.1'
 ext.conscryptLibraryVersion = '1.0.1'
-ext.evernoteLibraryVersion = '1.2.2'
+ext.evernoteLibraryVersion = '1.2.4'
 ext.gsonLibraryVersion = '2.8.2'
-ext.guavaLibraryVersion = '23.6-android'
+ext.guavaLibraryVersion = '24.1-android'
 ext.photoViewLibraryVersion = '2.0.0'
 ext.swipebackLibraryVersion = '1.0.2'
 ext.ratethisappLibraryVersion = '1.2.0'
diff --git a/app/src/main/java/fr/gouv/etalab/mastodon/activities/ShowConversationActivity.java b/app/src/main/java/fr/gouv/etalab/mastodon/activities/ShowConversationActivity.java
index bd6f74749..f22428e82 100644
--- a/app/src/main/java/fr/gouv/etalab/mastodon/activities/ShowConversationActivity.java
+++ b/app/src/main/java/fr/gouv/etalab/mastodon/activities/ShowConversationActivity.java
@@ -142,16 +142,17 @@ public class ShowConversationActivity extends BaseActivity implements OnRetrieve
             action_refresh.setOnClickListener(new View.OnClickListener() {
                 @Override
                 public void onClick(View view) {
-                    if( statuses != null)
-                    swipeRefreshLayout.setRefreshing(true);
-                    ( new Handler()).postDelayed(new Runnable() {
-                        @Override
-                        public void run() {
-                            isRefreshed = true;
-                            statusId = statuses.get(statuses.size()-1).getId();
-                            new RetrieveFeedsAsyncTask(getApplicationContext(), RetrieveFeedsAsyncTask.Type.ONESTATUS, statusId,null, false, false, ShowConversationActivity.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
-                        }
-                    }, 1000);
+                    if( statuses != null) {
+                        swipeRefreshLayout.setRefreshing(true);
+                        (new Handler()).postDelayed(new Runnable() {
+                            @Override
+                            public void run() {
+                                isRefreshed = true;
+                                statusId = statuses.get(statuses.size() - 1).getId();
+                                new RetrieveFeedsAsyncTask(getApplicationContext(), RetrieveFeedsAsyncTask.Type.ONESTATUS, statusId, null, false, false, ShowConversationActivity.this).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR);
+                            }
+                        }, 1000);
+                    }
                 }
             });
             action_expand.setOnClickListener(new View.OnClickListener() {
diff --git a/app/src/main/java/fr/gouv/etalab/mastodon/activities/TootActivity.java b/app/src/main/java/fr/gouv/etalab/mastodon/activities/TootActivity.java
index 6f13abe34..826884c24 100644
--- a/app/src/main/java/fr/gouv/etalab/mastodon/activities/TootActivity.java
+++ b/app/src/main/java/fr/gouv/etalab/mastodon/activities/TootActivity.java
@@ -807,6 +807,11 @@ public class TootActivity extends BaseActivity implements OnRetrieveSearcAccount
         @Override
         protected Void doInBackground(Void... voids) {
 
+
+            if( this.fileWeakReference.get() == null) {
+                Toast.makeText(activityWeakReference.get(), R.string.toast_error, Toast.LENGTH_SHORT).show();
+                return null;
+            }
             Bitmap takenImage = BitmapFactory.decodeFile(String.valueOf(this.fileWeakReference.get()));
             int size = takenImage.getByteCount();
             SharedPreferences sharedpreferences = this.activityWeakReference.get().getSharedPreferences(Helper.APP_PREFS, android.content.Context.MODE_PRIVATE);
@@ -836,6 +841,8 @@ public class TootActivity extends BaseActivity implements OnRetrieveSearcAccount
 
         @Override
         protected void onPostExecute(Void result) {
+            if( bs == null)
+                return;
             ImageButton toot_picture;
             LinearLayout toot_picture_container;
             toot_picture = this.activityWeakReference.get().findViewById(R.id.toot_picture);