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 windowA Unity Editor window that shows errors, warnings and other messages generated by Unity, or your own scripts. More info
See in Glossary. 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.