suddenly VM back-end doesn't display categories

[adnanjo]

Hello,

I am working on a store based on VirtueMart 3.2.3 , suddenly for ambiguous reason I couldn't see the categories in product page in back-end.
I've checked if there is a problem with JS, but it seems everything works well, but the categories list has not been loaded.
http://prntscr.com/gbcwmi

I am using a 3rd part program with VM, called "virtuemart manager" and it shows the categories correctly without any problems.
http://prntscr.com/gbd0ax

I have 4 different languages in the store, with about 500 category.

Any one has any similar issues, or has any idea about that?

Best Regards