4.12 Packing Failed -> AutomationTool Fatal Error


I got a big problem with the new Unreal Engine 4.12. I updated my game from 4.11 to 4.12 and everything was and is working great in the Editor (Play in Editor and Standalone). Now, as each weekend I tried to pack a new build to upload it for testing. Unfortunately the packing now fails with an fatal error under 4.12

Is there already a solution for this problem? The error message isn’t that usefull for me …

Found the solution. The conversion to 4.12 or a crash corrupt a map that forced the failure while cooking.
Copied the Map from the 4.11 backup and now it’s working great.

Have the same problem. How did you know it was the map?

Well I just started packing step by step. I createdan empty map and packed it without an error so I tought It could be a problem with the maps.

So I added one map after another and packed it and after adding this special map it crashed.

Ok, then it is like I would do. I thought, maybe there is a log file, where I can finde the part which cause the crash.

How do you pack step by step?

I have this exact same problem. Game will no longer package in 4.12. I cannot go back to the 4.11 version of my map as it was several weeks worth of work ago. Completely stuck.

PackagingResults:Error: Error Unknown Cook Failure

What am I supposed to do to fix it?