Hi

I am using latest osclass and Gama Theme. When trying to add a listing, I only can upload pictures with max_file_size of 2mb. I can configure in admin panel a different size max size but if I put any value greater than 2 mb, I receive error "reason unknown".

My server max size is configured at 52 mb.Owner of Gama Theme said something about "limit of gd library" could be the reason.
Any help?

I would say that reason is from gd library, it is very old and imagemagick is much better.
Consult with your hosting to install it on your server, it is usually standardly installed extension.

Thank you. It worked with ImageMagick

Great, so we have confirmed limit of GD 

I also want to thank you for your fast reply. Very helpful