TypeError: Error #1009: Cannot access a property or method of a null object reference at Main()

Game works properly and after upload to Mochi with "Use Live Updates?" = yes, doesn't work after preloader ad block says "TypeError: Error #1009: Cannot access a property or method of a null object reference at Main()"

FlashDevelop 4.3.0, FlexSDK 4.6.0 Air 3.6, Targeting FlashPlayer 10.1 Windows Vista Business 32 bit.

Do anybody know what's up?

Thanks in advance, have a nice day :)