I have the same problem; I can load up AI for the first time, change New Document profile to web and work as normal, but once I exit AI and open it again, it freezes whenever I try to start a New Document - and it only happens when I last worked in web document profile.

The only workaround I've found so far is holding down Command+Option+Shift while clicking the AI dock icon to open the program, which apparantly wipes the preferences file, and allows me to actually use AI and start a New Document.

It really is annoying, I hope Adobe fixes it sooner rather than later...

(Running CS6 on OSX 10.7.4)

for the record, i've narrowed it down to the EXACT file that causes the issue of the crash. When i delete it and start it, it runs great. but then when i close it and start it up again, it causes issues.

the file is

/Users/trza/Library/Preferences/Adobe\ Illustrator\ CS6\ Settings/en_US/Adobe\ Illustrator\ Prefs

its got seemingly fine permissions. i've taken screenshots of it all here

http://forums.adobe.com/thread/1031030

we've gotta figure this out. its so frustrating. upgrading to mountain lion is one idea, but i dont even like the way os x has been heading lately, i dont want to upgrade. im on 10.7.4 right now   

I can give everyone, <user>, and administrator to read & write, but how many folders back should i do that? naturally it's not good to do it to /

I suppose i can just try everything and revert back slowly. My /Users/trza/Library/Preferences/Adobe\ Illustrator\ CS5.1\ Settings is set the same as cs6. ugh this suck

Thanks so much for being so helpful with this.

Here is what I've done, I deleted the whole /Users/trza/Library/Preferences/Adobe\ Illustrator\ CS6\ Settings folder to start clean.

i started / closed illustrator cs6.

i changed permissions for everyone read&write and applied to enclosed items on /Users/trza/Library/Preferences/Adobe\ Illustrator\ CS6\ Settings

i started illustrator, still same problem. when i change from print to web, the app locks up (not responding) :\

Having the same issue. I've tried deleting the prefs, cache, and app support files. nothing has helped.

So it is then possible that the file for the Web Document Prrofile has the permissions problem

it is located here in the User/Username/Library directory

This is great that it works but.. what the hell. How do i prevent this from having to happen every time i close and reopen?

So basically I need to delete the preferences each time i open it. beacuse when i close it, it's writing it as sudo or something.

So can I either set up a custom launcher that launches it with that shortcut that rebuilds? Or can i make it so it doesnt screw with my preferences file when i close it?

There's gotta be at least a half automated way to get this working.

What do these preference files hold? what will i lose every time i keep deleting them? So far it doesnt look like it's changing much (Still same layout / presets / brushes etc stay)

thanks for the fix so far. much obliged.

This actually works, but seems to stop working after a restart. Is there a reason so few reports of this problem are found online?

You sound like a real person, Monika, and affiliated to Adobe, too. Please tell us if this issue is being addressed by Adobe, or if we're just out of luck to have bought a piece of software that doesn't work for us.

Fair enough. Current system settings is Mac OS 10.7.5, 2,93 Ghz Intel Core i7 and 16 GB 1333 MHz DDR3. Illustrator CS6 on this machine is part of the upgrade from the CS5.5 Master Collection. So far, I tried the manual override with CMD-opt-shift, adjusting the library settings to allow permissions and a reinstall.

The problem seems to occur when changing the new document profile to web, on which Illustrator invariably hangs.

My setup could well be at fault. If this information allows you to pinpoint the problem, I'd be much obliged.

I'm running from an admin account, but I did what you suggested and created a new user account with admin privileges. That new account had no trouble creating a new document as a web document, so you were right about the settings problem. Is there any way you know of I can use this information to fix illustrator on my regular admin account?