Looking at the crash log, it looks like you are missing Class Metadata for MixinNetworkItemManager.
I didn't have any other items in my inventory, just the Creative Controller
There was an import bus on pneumaticcraft's basic fluid tank next to where I placed the controller, with the default settings (item mode, etc) but given the crash log, I don't think it's a problem with RS trying to import into a system with no storage...? I'm not sure though. If you can't reproduce the problem without that, it's worth trying.
RSInfinityBooster version: 1.16.5-1.1+2 Refined Storage version: 1.9.15
Steps to Reproduce:
Additional Information:
Crash Log: https://gist.github.com/kd8lvt/d234177fbfe26deaa3d11b429674f39a