anything from any browser. Inserting a new track between two by dragging audio/midi/sample/instrument to project window. In 9.5 a green line appeared between two tracks and it created a new track
I think this is the behaviour the OP is on about, that has changed since 9.5:-
Previously fast and convenient NEW workflow introduced at v9.5 - drag part/sound to anywhere in the Arrange page, adjust position (‘between tracks’) to engage the green line and drop. Now a little crippled at v10.0 - restricted to hovering between tracks in the Track Header only and (having to) set the Cursor at desired place, first, to position your drop.
Ok I did some test in Windows 7. Running as admin did not work for me unless I changed UAC settings in control panel in Windows. If I set it to the lowest level and restart the PC then it works as expected.
If UAC settings is in default position then it doesn’t work. So it has definitely to do with Windows permissions not the program it self.