This can happen when SimpleMind was not installed via the Google Play Store. For example, you used another app/store to install SimpleMind.

The only way to fix this is to install SimpleMind directly in the Google Play Store. First make a back-up of your local mind maps (if you have any). Remove the app and install again from the Google Play Store.

Note! If you use SimpleMind Lite, it is not possible to make a back-up. Deleting SimpleMind will also delete your mind maps.