vsthost crash when open plugin editor or process audio

[jackadandy]

I create a mini vst host and sometimes it goes crash when opening plugin editor or processing audio data. It crashes when I call dispatcher(effect, effEditOpen, 0, 0, windowHandle, 0) or processReplacing(). It has nothing to do with plugins because it happens to different plugins serveral times. And I try some other hosts in github and find the crash happens in these hosts too. When the crash happens I could not catch and handle it. And I don't know how to handle it. Hopefully someone could shed some light on this.