Folders (files) cannot be deleted, renamed or moved?

What can be the reason?
I can’t delete, rename or move different folders, files?

My Nextcloud is in the web space of my provider “hosteurope”.

Who can help me?

Greetings Klaus

Probably your provider has disabled it?

I turned on maintenance mode today. After that I was able to delete some folders and data. The only thing I can’t get down is a folder with a file.

So this is a different error.