I'm trying to install 8.1.0 as a clean install. The process says it's installing database tables for a while then comes up with:

Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator at webmaster@ujd.ujdweb.co.uk to inform them of the time this error occurred, and the actions you performed just before this 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.

This happens in MS Edge, while in Chrome the install just never gets beyond saying that it's installing database tables... for hours.

However, I can install using the command line using the same location on the server and the same database.

I got the same behaviour when I tried installing 8.0.3.