Before 2 day when i started unity it gives me this message “unity requires that the permission of the project folder are set to read and write”
the project folder is set to read and write i repaired the permission with Disk utility still have the same problem
sorry i forgot to tell it gives me two choices “SET PERMISSION” or “CANCEL” even if i press “SET PERMISSION” it will quit directly
I don’t believe this has anything to do with repairing permissions with Disk Utility. That only affects certain system-related folder hierarchies and generally has nothing to do with third party apps or user files.
If I recall correctly, this happens if you build a standalone game and store it in the project folder. If you have any in there, try removing them before launching Unity again.
It isn’t supposed to crash when you hit ‘Set Permissions’, though. Maybe you could put in a bug report for that. 
Sorry what i mean when i press “SET PERMISSION” it didn’t response and quit dirctly
Hi,
I got a similar problem when I opened up the demo StarTrooper iPhone project today. I got a window telling me that the permissions needed to be set. I entered my admin password and then nothing happened.
Immediately after, as soon as I opened Unity iPhone… it immediately crashed without even an error message. When I opened Unity Indie, it also crashed (but this also gave me an error, and an opportunity to submit a bug to Unity.
Anyway, I was wondering whether or not this got solved, or if anyone has any insights… I’ve tried re-installing Unity, but no luck. The permissions of StarTrooper didn’t actually have any problems, and there weren’t any built apps in the project directories…
It would be nice to get this done… as I can’t do any development in Unity since it crashes upon startup. 
Thanks!
I am also having this issue - it just started today and I figured I would check here for some input. Nobody ever came up with an answer to this? Odd…
I definitely never properly figured it out unfortunately.
Not quite sure if it was related, but this seemed to lead me to a completely unbootable drive. I had to reinstall Leopard and migrate from my backup. Once I did that, it was solved… kinda. There is now one Unity file that asks me this, but I’m definitely not going to allow it to change my permissions (thankfully it was just a test file… scrapping it wasn’t that critical).
I don’t think you should select “Set Permissions”. But unfortunately I have no real answer. Hopefully someone else (with knowledge of the situation) sees this post and can contribute.
Good luck!
Bumping this as I found the cause of the problem:
for me it was a dead symlink which was in the root folder of the project; it became invalid when copying the project to my macbook.
Resolving the problem with the symlink made the problem go away.
You can track the cause of the problem by looking at the Console output of the Editor, it gives a clear error message and points to the root of all evil: