[ovirt-users] The web portal gives: Bad Request: 400

After the recent upgrade from ovirt Version 4.1.1.6-1.el7.centos. to Version 4.1.1.8-1.el7.centos The web portal gives following error: Bad Request Your browser sent a request that this server could not understand. Additionally, a 400 Bad Request error was encountered while trying to use an ErrorDocument to handle the request. Are there any hints how to fix it? BTW the rest API works as expected, engine-setup went without errors. Thanks, Arman.