unity 4.2.1 ios build crashes in ios7 device start-up

hi everyone~ I`m upgrading my ios app to obtain ios7 compatibility

but it keeps crashing in start-up with error message “Failed to load AOT module mscorlib in aot-only mode.”

Ive already read the solution "Problem: Program crashes and debugger reports: “Failed to load AOT module ... in aot-only mode.” Possible Causes: Unknown cause. Possibly another bug in the Unity iPhone build pipeline. Possible Solution: Delete the app in the device (using Xcode Organizer) then install it again. " I tried it but its not worked.

any solutions???