Error on browsing some pages "CSRF verification failed "

If you are using a tunnel to browse the site and you are using a different port that what the service actually runs on, this can happen.

Th site checks that the IP and port matches what was requested.

The site runs on port 443 ( HTTPS ) and you have setup a tunnel to access the service locally on port 12345. You use your local browser to connect to and the page loads.
The once you try and access some services, the page fails to load with an Error 403:

CSRF verification failed

The service is checking that the access was supposed to go to port 443, but sees port 12345.

Change the tunnel to a Dynamic Socks proxy and use that in your browser
change the port locally to the same port that the service is actually running on. ( E.g. 443 from the example above. )