Thanks for the hint, I did not know it is coming.
Anyway, I could replicate:
1. Set 2 emitters, 2 types (default and a new one)
2. Both link and set to stream (Idk if it has any meaning now)
3. Push "Reset System" at System tab
4, Set again new emitter and new type. At random places it gives this (or similar) GM message (eg. when I try to set the properties of Type)
I do hope it helps.