Assertion failed on debug builds

I’m trying to run a debug build of UE4 Editor on Win64 but whenever we click Play in editor we get assertion errors. There are no problems with development builds but debug specifically is unusable. We have tried WindowsNoEditor standalone and Editor builds (in debug configuration) and all fail with the same error:

Assertion failed!
Program: …ries\ThirdParty\FMODStudio\Win64\fmodstudioD64.dll
File: c:\jk\workspace\Build_1.5_UE4Libs_…\fmod_factory.cpp
Line: 184

Expression: 0

We are using version 4.5 UE4 and Fmod Version 1.05.08 Disabling FMOD fixes the problem (as you’d expect)

That assert indicates there are multiple copies of one of the global bus objects in the bank, which shouldn’t normally happen. We’ll need a copy of the bank files to see what is going on in your case.

If you email we can follow up from there.