The URL: shirts/101/ returns shirt// and simply displays the first page of the shirts listing page.
If I click on the shirt which links to shirts/101/ or type in that URL manually, I am redirected to the shirts listing page and it simply says shirts//
I downloaded the most recent version of the project and it still isn't helping.
I imagine that it might have something to do with the .htaccess file but I can't seem to find any errors.
I just had to clear my cache and it worked!
I discovered this using Chrome's developer tools.
Under the network tab I noticed the first call to 101/ was getting an error 301 Moved Permanently error. I noticed after that message it said "cached".
I cleared my cache and it worked!!!