I'm doing a fresh install of 5.7.5.6, The installation creates the db files, says, setting up admin user, then fails with the following error;

The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, webmaster@***.com.au 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 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

The server error log only states the a 500 error page could not be found.
I've never used the host before, but all the c5 checks came in with a green tick.
Never had this issue before.

Any help would be greatly appreciated,

Dale