Activation of Coming Soon Plugin crashes backend

Hi,

after having activated the coming soon plugin, I get this error message:

0 Failed opening required '/mydomain.com/administrator/media/plg_juxcomingsoon/soon.php' (include_path='.:/usr/share/pear:/usr/share/php:/usr/share/pear:/usr/share/php')

It is impossible to access the backend. I am completely locked out. Please advise how to solve this.

I am on Joomla 4.1.5 with php 8.0 and have the latest version of Coming Soon Plugin installed.

Regards
Uwe