You may follow the official procedure to detect what is running between Voicemeeter, Voicemeeter Banana... and later Voicemeeter8. See DetectVoicemeeterType function in the Matrix 8x8 source code example ("vmr_matrix.c" delivered in the Voicemeter Remote API package). static char * G_szBUSNameList_v1[2]={"BUS A", "BUS B"}; static char * G_szBUSNameList_v2[5]={"BUS A1", "BUS A2", "BUS A3", "BUS B1", "BUS B2"}; static char * G_szBUSNameList_v3[8]={"BUS A1", "BUS A2", "BUS A3", "BUS A4", "BUS A5", "BUS...
The problem is maybe more located in Voicemeeter configuration: especially the device / interface selected as output A1. This main stream must be stable before connecting any process to Voicemeeter. Did you fix this?