Could you please provide us more info about the thunderbolt display? Do you get any error message when thunderbolt display is connected? If so please send us a screenshot of the same. Also, do send us the Console logs that appear in Console app at the time of issue. Do let us know any other info necessary to regenerate the issue and test the same.
Comments
If I disconnect them it works on the laptop by itself.
Could you please provide us more info about the thunderbolt display? Do you get any error message when thunderbolt display is connected? If so please send us a screenshot of the same. Also, do send us the Console logs that appear in Console app at the time of issue. Do let us know any other info necessary to regenerate the issue and test the same.