Using the /profile command in any dimension causes the game to crash with the following crash log. I think this is the Wizardry mod in question.

Not to be confused with Electroblob's Wizardry. I think

crash-2018-07-31_22.23.07-server.txt

Sorry if this was already reported.

I would advice to also report this to the wizardry mod in question as it might be something I can't fix on my side.

Gotcha. Will do.

Wizardry dev here, @way2muchnoise your DummyWorld and FakeClientWorld are constructed such that instances remain in an invalid state from being a capability provider which has not gone through capability initialization. In this specific case, DummyWorld should be overriding has/getCapability to delegate to the wrapped world and the FakeClientWorld should do this during construction:

capabilities = ForgeEventFactory.gatherCapabilities(this, null);