[Tiki-devel] Issues with File Galleries in Tiki 27

Hi,

I have a Tiki 27.3 installation here. I can't upload .gz files to the
File Gallery. They appear as having a size of 0 and aren't saved to the
hard drive (no path and no hash in the database).

The installation was previously running on version 27.2, and I didn't
have these issues then.
Where should I look to troubleshoot this problem?

Thanks
Karsten