A Windows scaling mismatch can cause an enlarged, cropped or partly blank NVMS display. This is one possible cause, not a diagnosis of every black-screen problem.
Try the documented adjustment
- Close NVMS completely.
- Right-click its desktop shortcut and open Properties.
- Under Compatibility, open Change high DPI settings.
- Enable the high-DPI scaling override and select System.
- Confirm both dialogs and reopen the client.
Check the camera picture and controls. If the result is worse, close the client and undo the override. Send CJSC your Windows version, display scaling and client version if the problem remains.
Source and version
Reconstructed in CJSC’s own wording from the archived LTS instructions. Menu names can differ between releases.