This occurs because you are deleting the font glyph file that is being displayed on these themes. You could be deleting them manually from the sdcard/ZooperWidget folder, but more than likely you are using an app like CleanMaster that is deleting these automatically.
If this occurs, just delete the theme and reapply it from the theme store. Then, add Themer and Zooper to your CleanMaster ignore list, otherwise this will occur again.Anonymous commented
This happened to me too only I was messing with settings now there's empty folders or alphabet I ant figure out how to get out corrected