Packaging: Unknown Cook Failure

I’ve been working on this project for a couple of months now, thus the older version. And thus far I was able to solve every packaging issue, because the log provided a specific error I could fix. However, now the log only produces an unknown cook failure, without any other specific errors.

Maybe I am overlooking something, so I hope someone out there can spot the problem in the log.

I also created a new clean sample project, where packaging worked fine. Resetting the project settings and caches also didn’t help.

C:\Users\TheCrew\AppData\Roaming\Unreal Engine\AutomationTool\Logs\F+Programme+UnrealEngine4+UE_4.21\Cook-2020.07.19-11.40.20.txt Would really need to also see this log file

Here is the cook result.

I accidentally hid one of my Streaming levels in the main scene. That apparently causes the program to crash when trying to package said scene.