Error while uploding files to OJS 3.0

I’m having a problem when uploading files to the OJS after upgrade to 3.0

Whenever I choose a file and send it, the browser acts strange, discards the file, I have to choose it once more and when I click send I get the following error:

No file uploaded or invalid type.

What can be done here?

Hi @Wojciech_Francuzik,

Double-check that the files permissions on your files_dir (as configured in config.inc.php) permit OJS to upload files there.

Regards,
Alec Smecher
Public Knowledge Project Team