Unabled to start simulator (revIPhoneSetSimulatorSDK)

[elwin]

I am getting this RUNREV error message when I try to test my stack on the IOS simulator:
Unabled to start simulator <blah blah> revIPhoneSetSimulatorSDK

It might be because I loaded Xcode 4.2 Developer Preview 7,
Posted: August 31, 2011
Build: 4C177 (Snow Leopard)

But before I uninstall and reinstall, I thought I would throw it out here and see if anyone has any advice. BTW I have launched the simulator (/Developer/Platforms/iPhonSimulator.platform/Developer/Applications/IOS Simulator.app and the simulator runs fine.
4.0 not 3.2 though.

I am running LiveCode build 1451 version 4.6.4
(I tried to post pictures of the error and my settings and preferences but I can't post urls )
Any advice would be cool! Thanks..

[CALL-151]

Did you check Mobile Support in LiveCode preferences to make sure it's pointing to the directory where the iOS SDK lives? Do you have an appropriate test target selected (Development-->Test Target...)? If so, then you'll probably need to drop back to Xcode 4.1.

[elwin]

Yup, had the right directory under prefs as well as a proper development target. I have to do some stuff with the beta xcode, then I will try backing down again and retrying.