Thank you for the info.
Could you login into your QNAP administration. Then modify the url in your browser
Normally it should say
http(s)://hostname-or-ip-of-your-qnap:<PORT>/cgi-bin
for example:
http://192.168.0.100:8080/cgi-bin
Please add /qpkg/RoonServer/index.php?debug=1 at the end of the url.
In the given example above the full url would be:
http://192.168.0.100:8080/cgi-bin/qpkg/RoonServer/index.php?debug=1
You should now see the webinterface of the QNAP RoonServer again and a small text text block.
Could you copy/paste this text block and send it to me?