Foren / Cotonti / General / Can not upload files

Hello Community,

I have discovered for myself and Cotonti just testing. And the first thing I notice a lot of things that do not really work for me. Therefore, I would like to ask for your help Tung parking.

I'm using the latest version of Cotonti in the back and can not upload files. It is issued following error message:

The upload failed, maybe the file is too large, or the extension is not allowed?

How can I fix the problem? Can anyone help me? Thanks in advance!