Apologies for starting another thread with this title and on this subject, but I've run into a bit of a brick wall with the site I am administering (www.claritycareconsulting.co.uk).
In the past when I have encountered this issue I have followed other forum advice which is usually to delete the latest plug-ins installed until you can get back in, but I have tried that without success.
I've also tried changing the name of the theme file but that didn't seem to work and I have also tried changing the .htaccess file name, to no avail, although it did take down the site so I put it back quickly.
I worried about doing anything more without damaging the site (it is at least still running at the moment so any advice would be gratefully received.