WDK Driver builds but fails to load - where to start?

Question

I'm able to build this driver ( scream )

I installed the WDK Test cert into my trusted root CAs and I can install the driver.
I used the bundled devcon utility - I don't know if that's a problem - it works with the github version.

After installing eventlog shows an Application popup with

\SystemRoot\system32\drivers\Scream.sys failed to load

and a kernel-pnp warning event id=219
The driver \Driver\Scream failed to load for the device ROOT\MEDIA\0000.

I haven't made any changes to the code. I installed the WDK for 10.0.17763.0 and built in VS2017. I tried building in VS2019 with the latest WDK and same problem.

1>
1>Catalog generation complete.
1>C:\scream\x64\Win7Debug\Scream\scream.cat
1>Done Adding Additional Store
1>Successfully signed: C:\scream\x64\Win7Debug\Scream\scream.cat
1>
1>Done building project "Scream.vcxproj".
========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========