Deleting of the photos may not succeed if there are some animated files that have been saved to the Gallery > Images > All folder during installation of certain 3rd party applications.
The issue has been fixed in the applications which are known to cause this problem but there may still exist some additional applications where the problem can occur.
The problem can be fixed in the following way:
- Start File mgr. by selecting Menu > Applications > File mgr.
- Select Phone memory
- Select the folder with the name of the installed application, e.g. "sogou".
- Highlight “skin” folder and select Options > Delete.
As the result the folder Menu > Gallery > Images > All will be cleaned of the animated photos which were introduced to the phone via installation of the application. Deleting of the photos should now work properly again.