Attempting to run Fedora workstation 21 Alpha TC5 led to a crash at the login screen with "Oh no! Something went wrong!". Test is done on a powered Intel 945GM laptop. The same system runs on the latest update of Fedora 20 featuring Gnome Shell 3.10.2.

Bugzilla report below:
https://bugzilla.redhat.com/show_bug.cgi?id=1136703

Posted following Ankur Sinha aka FranscisoD's suggestion.

--
Luya Tshimbalanga
Fedora Design Team
Design Suite spin maintainer