In case somebody else runs into this problem. Already sent a bug report so I use the same text for this posting as I used there. 1. What happened =========== After importing the "TMP Essentials" which Unity proposes after using Text Mesh Pro the first time newly created prefab instances will show TMP overrides you can't get rid of. (See screenshots showing the steps) Unity Version: 2018.3.1f 2. How we can reproduce it using the example you attached ==================================== 1. Create a new empty Unity project 2. Add a new TMP gameobject via GameObject->UI->Text Mesh Pro Text 3. Turn it into a prefab 4. Observe that the GameObject doesn't show any overrides 5. Now do the import of TMP Essentials as shown in screenshot #4 6. Repeat steps 2-3 or copy the existing TMP gameobject 7. Observe that there is now a TMP override as shown in screenshot #5 and #6. You can't get rid of it using apply/revert.