TFS 2010 Web Access Client shows Error 500 (Request was rejected by http filter)

We recently published our TFS Web Access Client via HTTPS to the outside world. Everything was working fine until we pressed the “Edit Query” button.

A Internal Server Error (500) appeared with the extra info “Request was rejected by http filter).

We are using Microsoft TMG server to publish the Web Access Client.

This link from Microsoft informs a bit about HTTP filtering on TMG. http://technet.microsoft.com/en-us/library/cc995081.aspx

After searching a while it appears you have to configure the publishing rule in TMG for the Web Access Client as follows.

Make sure that Verify Customization is unchecked!