I don't understand - what do you mean thumbnail images in "app manager"? Do you mean "file manager"?

When you say rebooting isn't an option, rebooting is just turning it off and back on, why is that not an option? Frankly rebooting may be the solution. If you mean 'reflashing' that's something else.

For what it's worth, I don't think I ever have been able to see thumbnail images while browsing folders in "file manager', I can only see thumbnails when I browse folders using the "Images" application.

....


OK never mind apparently there is a setting in 'file manager' under "view" for thumbnails. Works for me. Don't have any idea how to fix your problem, sorry to bother you.