When you report a problem to Unity, the Unity Support Team might need you to enable diagnostic switches to help identify the cause. Running diagnostics on an application, whether in the Editor or a Player, impacts performance and user experience. You should only run diagnostics when the Unity Support Team requires them.
To open the preferences, go to Edit > Preferences > Editor Diagnostics (macOS: Unity > Settings > Editor Diagnostics).
If diagnostic switches are active in your application, Unity displays a warning in the Console window. To reset switches, in the Editor Diagnostics tab, click Reset all.
If an active diagnostic switch prevents the Unity Editor from opening, use the --reset-diagnostic-switches parameter to reset all switches from the command line. For more information on using command line arguments at launch, refer to Command line interface.