Can’t Get Passed index.php page on WP MU

I type in my server address in a web browser. It brings up the “Welcome to WordPress..Installing Word Press Screen” They want me to type in the database name, username, pasword, etc. I type it all in a hit submit.

Then it shows the https://’mywebaddress’.indexs.php page, but it is blank. If I type in my server address in the browser, I get the same “Welcome to WordPress”

Any help…greatly apprecitaed!