On one machine running the same project that is on multiple other systems we get this crash:
"Unknown exception - code 00000001 (first/second chance not available)
Assertion failed: ShaderRef != NULL && *ShaderRef != NULL [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.7\Engine\Source\Runtime\ShaderCore\Public\Shader.h] [Line: 926]
Failed to find shader type FPostProcessVS
"
That same machine can run other UE4 Projects fine. The problem project runs fine on multiple machines and I verified all the data is the same. It looks like a shader or DX problem but I ensured the latest drivers and DX are on the machine.
Hi Jeff -
Can you give me some details to what type of project is causing this issue? Can it be reproduced in a First or Third Person Template Project on the one machine? If you are dealing with a GitHub version of the engine, have you rebuilt the engine solution? If you are dealing with source control, are there any files which may be old and not correctly syncing? As much information as you can give us would help us narrow down the possible causes. Also make sure if you are not already, please upload the crash reporter information and paste your Machine ID here.
Thank You
Eric Ketchum
Thanks Eric,
This is a machine just running the download version of engine from Launcher.
My other project based on FP C++ works fine. I just made a new Blueprint Third Person and it worked fine also. So clearly something wrong with our content of that game but it works fine on all other machines.
All files in project are synced correctly and I removed the Intermediate files a couple of times to rebuild. I also tried both 4.7.6 and 4.8.0 P3.
MachineId:749F9120454E83901B94C58B992AF1BB
Hi Jeff -
What are the Post Process settings that you are using in your project, in particular are you using an ambient cubemap?
Thank You
Eric Ketchum
I didn’t see any ambient cubemaps in our scenes. But it isn’t even getting that far so I am not sure what scene it would be loading. I even tried deleting all the scenes.
I may need to copy all those assets into another project and see when it breaks.
Hi Jeff -
After you run your tests, let us know if we can help you in anyway.
Thank You
Eric Ketchum
After a lot of tests, I determined that a couple of minor changes (which I am not sure how someone made) cause the crash. Resetting these lines from DefaultEngine.ini allow it to run. Then if I set them again after it runs once it works.
This only so far seems to have happened on two machines. But is definitely related to how shaders are generated.
These lines cause it to crash:
r.EarlyZPassMovable=True
r.DBuffer=True
Setting them to default causes it to work again:
r.EarlyZPassMovable=False
r.DBuffer=False
I could then change them at will. Since I don’t believe we intentionally changed those and were likely just messing around, I am reverting. Hopefully that will help someone.