I thought I found the issue. 
It hadn’t occured since I disabled the PMS50 add-on until today today. PMS50 add-on is disabled and I got black screen on the displays. However the pop outs should the displayed correctly.
I thought I found the issue. It hadn’t occured since I disabled the PMS50 add-on until today today. PMS50 add-on is disabled and I got black screen on the displays. However the pop outs should the displayed correctly.