Using a home computer has it's own issues.
I have used xampp and wamp but never nginx.
But here is what it does for me.
You can't use a alias domain name if accessed outside of the pc local lan..
Thats what spider frendly urls attempts to do.(create a url from outside of your lan)
So it goes outside of your network and looks for it.
Even if you use a virtual path.once you click on the first link it is broken.
Unless you have registered a name with dns pointers to your pc.
Your site will use your public ip ,whatever that is unless you have a registered name with that ip.
And a home computer usually has a dynamic ip.
Note: The PATH_INFO environmental variable must be available for this feature to function properly.
So say you have a pc at local lan 192.168.0.20 you need to find your public ip like at "find my ip".
It will be unlike the ip range of your router
Use that as a port forward. in the cable modem.
Then you need to change the paths in ubb to match that IP..
as well as the alias url
So it will endup as http://##.##.##.###/forums/?????/html
I hope that was clear as mud.
Maybe somebody can explain it better than I can.