diff --git a/app/release/app-release-4.0.3.apk b/app/release/app-release-4.0.3.apk
new file mode 100644
index 0000000..bdcbc30
Binary files /dev/null and b/app/release/app-release-4.0.3.apk differ
diff --git a/app/release/app-release-4.0.2.apk b/app/release/old_versions/app-release-4.0.2.apk
similarity index 100%
rename from app/release/app-release-4.0.2.apk
rename to app/release/old_versions/app-release-4.0.2.apk
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 99a5e43..910a93b 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -3,7 +3,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     package="uk.org.openseizuredetector"
     android:versionCode="100"
-    android:versionName="4.1.1">
+    android:versionName="4.0.3">
     <!-- android:allowBackup="false" -->
     <uses-permission android:name="android.permission.BLUETOOTH" />
     <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
diff --git a/app/src/main/java/uk/org/openseizuredetector/LogManagerControlActivity.java b/app/src/main/java/uk/org/openseizuredetector/LogManagerControlActivity.java
index 2321f47..ef1e59a 100644
--- a/app/src/main/java/uk/org/openseizuredetector/LogManagerControlActivity.java
+++ b/app/src/main/java/uk/org/openseizuredetector/LogManagerControlActivity.java
@@ -428,8 +428,16 @@ public class LogManagerControlActivity extends AppCompatActivity {
                 return true;
             case R.id.action_mark_unknown:
                 Log.i(TAG,"action_mark_unknown");
-                mLm.mWac.markUnverifiedEventsAsUnknown();
-
+                new AlertDialog.Builder(this)
+                        .setTitle(R.string.mark_unverified_events_unknown_dialog_title)
+                        .setMessage(R.string.mark_unverified_events_unknown_dialog_message)
+                        .setIcon(android.R.drawable.ic_dialog_alert)
+                        .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
+                            public void onClick(DialogInterface dialog, int whichButton) {
+                                mLm.mWac.markUnverifiedEventsAsUnknown();
+                            }})
+                        .setNegativeButton(android.R.string.no, null)
+                        .show();
             default:
                 return super.onOptionsItemSelected(item);
         }
diff --git a/app/src/main/java/uk/org/openseizuredetector/WebApiConnection.java b/app/src/main/java/uk/org/openseizuredetector/WebApiConnection.java
index 43ebd3a..00776fd 100644
--- a/app/src/main/java/uk/org/openseizuredetector/WebApiConnection.java
+++ b/app/src/main/java/uk/org/openseizuredetector/WebApiConnection.java
@@ -165,11 +165,13 @@ public abstract class WebApiConnection {
                                         markEventsAsUnknown(eventList);
                                     } else {
                                         Log.e(TAG, "markEventsAsUnknown.updateEvent.callback - eventObj is null");
+                                        mUtil.showToast("markEventsAsUnknown.updateEvent.callback - eventObj is null");
                                     }
                                 }
                             });
                         } catch (JSONException e) {
                             Log.e(TAG,"markEventsAsUnknown.getEvent.callback: Error editing eventObj");
+                            mUtil.showToast("markEventsAsUnknown.getEvent.callback: Error editing eventObj");
                         }
                     } else {
                         mUtil.showToast("Failed to Retrieve Event from Remote Database");
@@ -179,7 +181,7 @@ public abstract class WebApiConnection {
             });
         } else {
             Log.i(TAG,"markEventsAsUnknown(): No more events to Modify");
-            mUtil.showToast("No unvalidated events to modify :)");
+            mUtil.showToast("No more unvalidated events to modify.");
 
         }
         return(true);
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index ba03c31..6623440 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -3,9 +3,9 @@
     <string name="app_name">OpenSeizureDetector</string>
     <string name="changelog">
         "\n
-        \nV4.1.1 - Changed remote database to be compatible with either OSD webAPI or future Firebase database.<br/>
+        \nV4.0.3 - Changed remote database to be compatible with either OSD webAPI or future Firebase database.<br/>
            - Performance improvement by having separate events and datapoints tables in local database
-        \nV4.0.1 - fixed crash in Report Seizure function
+        \nV4.0.1, 4.0.2, - fixed repoted crashes
         \nV4.0.0
           - Introduced the &lt;b>Data Sharing&lt;/b> feature to allow users to share their seizure and false alarm data
         with researchers to help improve the system.&lt;br/>
@@ -435,4 +435,6 @@
     <string name="about_data_sharing">About Data Sharing</string>
     <string name="privacy_policy">Privacy Policy</string>
     <string name="mark_unverified_events_as_unknown">Mark Unverified Events as Unknown</string>
+    <string name="mark_unverified_events_unknown_dialog_title">Mark All Unverified Events as Unknown?</string>
+    <string name="mark_unverified_events_unknown_dialog_message">Please confirm that all genuine seizure events have been verified before marking all unverified events as type \'unknown\'.   \n\nContinue to mark unverified events as Unknown?</string>
 </resources>