Getting an com.google.common.collect.ComputationException: java.lang.NullPointerException Error

Hi,

This error com.google.common.collect.ComputationException: java.lang.NullPointerException constantlly appears in my Flex 4.7 AIR SDK 3.5 and it prevents me from making an IOS mobile realease build.  When developing I can make it disappear with a Clean.  But it always reappears when I attempt to do a release build.

Thank you