The portal won't work unless it has been correctly configured - are you able to confirm that you've set this up with at least one published API (details on how to do this can be found here)?
If setting that up still doesn't work, it might be worth adding a trailing forward slash to the end of the URL when making a GET request to it (i.e.,
www.tyk-portal-test.com/portal/). Let me know if that works or if you're still having trouble with your portal.
Jess @ Tyk