The server returned a "500 error for Joomla 4

I installed Ja Insight Joomla 4 but I get following error. I tried twice.

Did you update Joomla or just install JA Insight template and this error appears?

I enabled the debug mode and it looks like the error comes from the core plugin of Joomla.

I just installed JA Insight template and this error appeared. I even tried twice, deleted all files in server and installed the template.

I will delete everything and try to install again.

I installed a new template - JaSpace. I had following error and the solution https://github.com/joomla/joomla-cms/issues/38474

I deleted the file manually as they suggested and it worked.

All now fine.

Glad to hear that 🙂