Went to backup my website database in C5 dashboard, systems and settings forhttp://www.getthebigidea.co.uk before upgrading to the latest version of Concrete5 and got the following message:

"Internal Server Error

The server encountered an internal error or misconfiguration and was unable to complete your request.

Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request."

Can anyone tell me what the means (in non-techie talk) and what I can do to fix it please?

I have nothing on the server and have run this backup successfully several times before on this website, ...but now I can't!!!!