Hello levinho,
sorry that you're having issues, however, overriding material in the content browser works for me correctly in IR, no freeze/crash.
We're aware of the issue with the normal map, unfortunately, it didn't quite fit into the hotfix.
Does the material override issue happen in any scene or one in particular? If in any, would it be possible to create a short video displaying your steps to reproduce it? If in one in particular, would it be possible to send the scene (or its minimal form) over to us? This would help greatly with investigation.
Thanks,
Jan