Hello folks!! I got stuck with this bugging bug!! and I just HAD to share it. So, I had a Main SWF that loaded up a MapClass swf and a SHELL that loaded up the Main swf. Everything worked when I debugged the Main SWF alone. But as soon as I debugged the shell, I got the following error. Exception fault: TypeError: Error #1034: Type Coercion failed: cannot convert a.b.c::MapEvent@c899eb1 to a.b.c.MapEvent. at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at com.iomedia.components::MapDocumentClass/onMapButtonClicked() My Project structure was <Root> <src> <a> <b> Main.as Shell.as <c> MapDocumentClass.as MapEvent.as <fla> <maps> MapClass.fla //SRC path set as "../../src" DOCUMENT CLASS: a.b.c.MapDocumentClass Basically, I had 3 levels of nesting of swf's. SHELL SWF <- MAIN SWF <- SHELL SWF When I compiled the Main.as file it automatically compiled the event class and had it ready for the Erroneous Swf to use. So everything was peachy! However, when I compiled the SHELL SWF, it didn't compile the Event Class because there was no reference to it in the Shell.as class. The solution : 1) Create a dummy variable for the event in the Shell.as class 2) Import the Event Class so that it gets compiled. Everything worked after that!!