If you are unable to run the Showkase Server Compatibility Test, then the problem might be something as basic as not having PHP installed (or correctly configured) on your web server.
Try contacting your web host to see if they can confirm if you have PHP installed on your hosting account and, if so, which version.
The problem may also be a pathing problem whereby the URL you are entering into your browser's address bar may be incorrect and you are not actually viewing the Showkase Server Compatibility Test or Showkase admin section files at all.
Please double-check that the URLs you are using are correct.
Also, please check to see if you have any rewrite or redirect rules in an .htaccess file on your web server which might be causing your problem.
It might also help if I were able to see the problem for myself so please post the URLs to your Showkase Server Compatibility Test and Showkase site itself and I will take a look and investigate further. Thank you.