Default kb2962407 causing jailbreak to hang

Has anyone installed the optional update kb2962407 (published 6/10/2014) on their Windows RT 8.0 Device? I installed it last night and after rebooting the jailbreak hangs at "getting signing level". I've been using version 1.13a for a long time now, so I went and downloaded 1.20 which got stuck at the same spot. System doesn't crash or BSOD or anything, just nothing further happens in the PowerShell window. It should prompt for the volume up, down etc. I know it was well past the two minute uptime. Tried rebooting a few times too.

Fortunately after uninstalling this update the jailbreak started working again. Big sigh of relief...

Just curious if anyone else has experience issues with this update and the jailbreak?