NullPointerException when exporting for iOS

I have an AIR for iOS project that runs fine in the simulator, but when I try to export a release build and click on 'finish', then it starts compiling and after a minute or two, i get a

Exception in thread "main" java.lang.NullPointerException

at adobe.abc.GlobalOptimizer.sccp_eval(GlobalOptimizer.java:6944)

at adobe.abc.GlobalOptimizer.sccp_analyze(GlobalOptimizer.java5909)

at adobe.abc.GlobalOptimizer.sccp(GlobalOptimizer.java:4628)

at adobe.abc.GlobalOptimizer.optimize(GlobalOptimizer.java:3514)

at adobe.abc.GlobalOptimizer.optimize(GlobalOptimizer.java:2215)

at adobe.abc.LLVMEmitter.optimizeABCs(LLVMEmitter.java:526)

the logfile doesn't capture anything.

Anyone an idea what could cause this error?

I compiled other projects successfully for iOS.