Unity Editor has stopped responding on Play.. DX11 issue?

With DX11 on Windows 7 64bit using Unity 4.3.2 when I press Play the editor just hangs and is no longer responding. I have to then end the unity process as it has stopped responding according to task manager. There is no errors. There is no bug report log. There is nothing. How am I supposed to debug this? The only workaround I could find was to set Edit > Graphics Emulation > Shader Model 3 and it seams to be ok in the last 3 attempts, but if I set it back to No Emulation it becomes extremely iffy on whether it feels like playing or not. I'm guessing OpenGL probably works fine, but I want Deferred Lightning so I need DX11.

 

Could someone from Unity please comment on this? This is getting ridiculous. How am I supposed to work on my game when this editor keeps crashing.

 

I think I may have found what script is causing this issue. It still would be of massive help if there was some way to debug this. If there is then please provide some sort of tutorial so we can properly debug editor issues.

 

I have the same problem. While modifying my programme to instantiate prefabs unity froze – no buttons worked and I could not even close the program. The only way forward was to use the task master to end the programme and even then it sometimes took several attempts before tit succeeded. There were no error messages nor I can read my scripts to see whatever might have led to this problem.

I have tried to delete and reinstall my individual copy of unity, but this has had no effect. Please could someone from unity make some sort of suggestion as to how this superb programme could be amended to work correctly.