Catalina MacBook Air — Thunderbolt Display not initializing

Hello K1200LT,

Welcome to Apple Support Communities. I understand that since upgrading to macOS Catalina, your thunderbolt display connected tom your MacBook Air shows blank black. Yet, if you start the Macbook Air without the Thunderbolt Display connected shows the display as expected. I’m happy to help .

Please try the steps here: Get help with video issues on external displays connected to your Mac - Apple Support

I also recommend testing in a test user account to rule out any user profile issues here: How to test an issue in another user account on your Mac - Apple Support

Take care.

I have a 15-inch Later 2013 MacBook Pro and use a Thunderbolt Display at home and an external HDMI connected monitor at work. Since updating to Catalina (now 10.15.1) the MacBook only periodically recognises the Thunderbolt Display when waking from sleep. It always connects to the Thunderbolt Display when re-booted. When it does connect to the display it rarely recognises the services (USB, camera and sound) connected through the display. The monitor at work always seems to work. The 'Detect Displays' button in System Preferences does not cause the display to detect the Thunderbolt Display.

I can charge an iPad from the display's USB port when the computer is not connected but when the computer is connected the iPad stops charging.

The MacBook is also crashing frequently, which I suspect maybe related to the display. I have completely reinstalled the MacBook from scratch (i.e. manually installing OS, Apps and data) and while it is now crashing less frequently (one daily) compared to several time daily before the install.

Any suggestions greatly appreciated.

Welcome back K1200LT,

Thanks for letting me know that you have installed the beta and your issue has been resolved.

Take care.