Okay, just to make it clear: I will not try to work around snake-oil software injecting itself into my software and then causing havoc, and most likely there isn't even anything I can do about it. You will have to report to ESET that their software makes other people's software crash.

To give you a slightly less pissed-off rationale: ESET injects a library called ebehmoni.dll into OpenMPT and then there is a crash in this library. Since neither my code nor your VST plugins' code calls into this DLL, we cannot know which code path leads to this crash and why. If I call e.g. into a plugin and it then crashes, I can reason that this crash is related to my call into the plugin, but since I do not call ebehmoni.dll at all, I cannot tell you why it suddenly is part of my process and what it is doing there and why it's crashing. The only thing you can do here is stop using ESET and tell them their software is broken.