Question Add files

However, joomla 3 with kunena worked fine on the same server, so do you think its the server?

aha you write
"The add button works as file manager pop up, and clicked on a file and I got this error Failed to open upload input stream."
on which file do you click that are on your PC/laptop. can it not be the security of your own pc/laptop which then blocks
you on the chosen pc/laptop folder.
Are other forum users experiencing this as well?

or then maybe something in the php settings.
do they match the minimum requirements stated here?
www.kunena.org/docs/en/basics/requirements/requirements-k6-0
and here I read something Check for open_basedir restrictions
bobcares.com/blog/joomla-there-was-an-er...-file-to-the-server/

i HAVE GOT IT WORKING ON MY TEST WEBSITE.

PHP version was 7.4.30 so I switched it to 8.0.21

But On the original website, when I switched it to 8.0.21. I got 403 error so I will need to rebuild the website as something is stopping it.

So Happy I have found the problem

Thank you for your help

Karl

set the debugging on the original website to high there may be an old plugin or extension that can't handle the new php version.
and if you have a higher php version try that too

I have found the program, its JChatSocial Enterprise Edition and its up to date too so I will email them!

ok so it works if you turn off that JChatSocial?
do you also have with other php higher version 8.0.21.  tested?
Let us know here what their solution is so that others can also benefit from it