I connected my tablet to the PC but the second screen was black although the mouse was working. The screen started working when I launched the game osu! Previously, everything was fine on the old PC, but something is wrong here. I re-installed and looked for guides but nothing on this topic
Could you clarify what you mean by ‘The screen started working when I launched the game osu!’ Has the issue been resolved?
What connection type are you using (Wi-Fi/USB)?
What is your second screen? (Windows/Android/iOS)?
Could you please check for any incompatible software, just run the spacedesk Driver Console -> Diagnostics -> Incompatible Software Products. if there is, please uninstall or disable it and try again with spacedesk