Why is there a grey rectangle blocking my screen?

Virtual external displays (monitors) are not permitted when using Exam4. This includes the use of screen capture tools and OS features such as Sidecar.

  • If you are using some kind of screen capture tool, stop using it and restart Exam4.
  • If you are seeing the image below, this may indicate that Sidecar is active on your Mac.
    Disable Sidecar in System Preferences and try again.


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