I have send you a pm
I fix your problem
.
So issues was exactly where I think it is. Somehow you have translated english language definitions to your language and few of them broke javascript.
What were fixed:
Admin > Localization > Language Definitions then language definitions with key tab_media and text_media were renamed from
Foto's to
Foto\'s I will report issue to AbanteCart team to avoid this problem in new version.
Thank you.