Sudden Error: "It looks like you are trying to reinstall your Nextcloud. However the file CAN_INSTALL is missing from your config directory. Please create the file CAN_INSTALL in your config folder to continue."

ℹ️ Support
4

In my case the problem was a corrupted config.php due to the server disk being full. I’ve restored a backup and solved the problem.
Thank to @erik09 and his post.