JEM 4.5 Attachments failed

The "media/com_jem" directory does exist, but the problem is that when I try to add an attachment to an event specifically in the "Attachments" tab, nothing appears when I click the "+" button.
So, I am unable to add attachments.

Hi !
The problem seems to stem from the template I am using for my site—which is not the default "Cassiopeia" template but one from TemplateCreatorCK. In fact, I installed a clean version of Joomla 6, and adding attachments worked perfectly with JEM 5.0.
What should I do to fix this issue?
Do you have any ideas?

So when you say Cassiopeia, you mean the "+" button for attachments is on the frontend, right? Because on the backend, the default Joomla admin template works fine and you can add attachments to the event, correct?

Does your browser have any JavaScript limits, or does the template stop JavaScript from running?
I saw the "Template Creator CK 5.6.0" supports Joomla 6, do you have this version installed?
 

It turns out my TemplateCreatorCK template isn't the cause. I installed the template on a clean Joomla site and was able to create attachments using JEM 5.0.
I suspect the issue lies with my database, though I'm not sure which specific element is causing it. I plan to optimize the database and remove tables belonging to components that have already been uninstalled.
I'll keep you posted on the outcome.

OK, best of luck. You could try unpublishing a few plugins and then compare your clean Joomla installation with the production one.

I wanted to import my events from my production site to my test site, and I'm getting this message.

Import blocked for security reasons. Unsafe import data blocked: introtext contains blocked HTML tagsHow can this problem be solved?