I used the plugin with Tempera and an old version od WP, now with WP 5.9. I can’t let the plugin be active, bc I can’t then access the dashboard of WP. How can I customize Tempera now? Maybe it’s possible for dummies without that plugin?
You don’t need to worry because it often happens like this. Same happened to me when I installed WP in a client’s website, his website which was related to winch also had the same problem but soon I googled about it and Redesigned the client’s website with WP.