nDisplay active stereoscopic view

Hi guys,
I have set up nDisplay according to the documentation. The System I am using is back-projection-system with active stereo view. Thus we use shutter glasses. Two Clusters are used to render a picture for each eye, which is played in a frequenze of 60hz (120hz total). Mono render mode is no issue. However I have Problems delivering a picture for one eye for one monitor and an other to the other monitor. If I try Frame Sequential I get a error message.

Kind regards