Error on login - file not found

I have setup a new site in C5.8.x.x

But upon trying to login for the first time I get a big error panel.
How can I resolve this easily please?

I originally had the site in a concrete8 directory for development before moving to the root.

Did you try to empty the application/files/cache directory?

If you are starting from scratch you might consider using version 9 also, if that’s a possibility for you. :+1: