So, this is probably going to sound a bit of a stupid problem but here goes anyway.
I've just set up XAMPP on my Linux installation for local development of a website. I installed Metropolis theme using the RocketLauncher which went without problem except for a warning about writing to the configuration.php. I followed the Joomla install instructions for sorting this out, opened my test website (localhost/metropolis) and came across the error message in the subject.
The problem is that I honestly have no idea how to fix this as I'm kind of new to websites. Any help would be great!
Yeah, I realised that just before I noticed your reply
Just out of interest, to get around the problem I just set the whole website root directory to 777. Would the permission just actually need to be changed on a specific file(s) and if so which would be the best permissions to use? 664?