When in the Object Browser and select an object, right click and select 'Highlight on Screen', it tells me "Cannot highlight this object on screen."
However, it will work correctly if I don't have a project open up in TestComplete. If I turn on TestComplete, but don't open up a project, go to Object Browser, right-click on an object, select Highlight, it will successfully highlight the object. But once I open up a project suite in TestComplete, then it will no longer highlight the object.
I double checked these steps with TestComplete 12.42 and it works correctly. Makes me believe there is something wrong with 12.50