Do you have Nvidia as your main graphics adapter?
If yes, please make sure that Nvidia ShadowPlay/In-game overlay/screen recording is disabled while spacedesk viewer is connected.
If the suggestion above did not help, please send us the diagnostic logs of this issue.
Just follow the steps below:
– open the spacedesk Console window app by clicking the spacedesk tray icon on your task bar’s notification area
– click the Diagnostics on the left side panel
– if Debug View is not available, please click the download button first
– switch Diagnostic Collection ON (make sure to click Yes in the User Account Control box to proceed)
– connect your viewer app and reproduce the black screen issue
– switch Diagnostic Collection OFF
– click Save All Information button (if message box appears, just click No to proceed)
PS: Saving all information will take a few seconds, then please send us the whole folder which contains all the diagnostic logs collected.
Please right-click the folder -> Send to -> Compressed (zipped) folder, then attach the *.zip file in your next reply.