Error communicating with FME Server host localhost

Hello community,

for a few days, I have been struggling with our FME Flow. It occasionally throws

and 

I am the admin, I asked myself and… crickets.

The only change we did recently is a Python library install.

FME Flow gets in this error communicating state and then recovers. We tried restarting FME Flow, it likely made some difference (I am not sure whether it indeed fixed the problem even for a short period of time as FME Flow works between these messages anyway), but it didn’t last.

This is FME Flow 2024.0 build 24612.

Any ideas will be much appreciated.

Thank you :)