I have gotten this error twice in the past two days with two different plug-ins which installed fine previously.
The website encountered an error while retrieving http://www.aka.org/aka2test/wp-admin/. It may be down for maintenance or configured incorrectly.
HTTP Error 500 (Internal Server Error): An unexpected condition was encountered while the server was attempting to fulfill the request.
I cannot access the Admin section at all. I've done a database check and repair (without anything being broken)which means I had to start all over from scratch and put in 15-20 hours of work until it failed again.
The actual frontend website seems to run fine, but now I can't do any fresh work that I absolutely have to complete.
If anyone has any idea other than backing up the site every hour (which I guess I will have to do now) please.