I've decided to "port" my latest project from Flex 3 to Flex 4.
And with some modifications I got it running again (with all mate parts commented-out, just to be sure).
After that I've uncommented only one XEventMap class to my surprise there were no errors, until I ran application again. The problem sticks inside EventHandlers and also Injectors (maybe more), maybe the problem is inside of AbstractHandlers class, dunno.
Here is the ErrorLog:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at com.asfusion.mate.core::GlobalDispatcher/get popupDispatcher()[/Users/Miran/Documents/SVN/mate-framework/com/asfusion/mate/core/GlobalDispatcher.as:61]
at com.asfusion.mate.core::GlobalDispatcher/addEventListener()[/Users/Miran/Documents/SVN/mate-framework/com/asfusion/mate/core/GlobalDispatcher.as:86]
at com.asfusion.mate.actionLists::EventHandlers/commitProperties()[/Users/Miran/Documents/SVN/mate-framework/com/asfusion/mate/actionLists/EventHandlers.as:229]
at com.asfusion.mate.actionLists::AbstractHandlers/validateNow()[/Users/Miran/Documents/SVN/mate-framework/com/asfusion/mate/actionLists/AbstractHandlers.as:266]
at com.asfusion.mate.actionLists::AbstractHandlers/setDispatcher()[/Users/Miran/Documents/SVN/mate-framework/com/asfusion/mate/actionLists/AbstractHandlers.as:239]
at com.asfusion.mate.actionLists::EventHandlers/setDispatcher()[/Users/Miran/Documents/SVN/mate-framework/com/asfusion/mate/actionLists/EventHandlers.as:186]
at com.asfusion.mate.actionLists::AbstractHandlers/initialized()[/Users/Miran/Documents/SVN/mate-framework/com/asfusion/mate/actionLists/AbstractHandlers.as:409]
at com.loncaric.xxx.maps::RegisterEventMap/_RegisterEventMap_EventHandlers1_i()[/Users/Miran/Documents/Flex Builder 3/ddd_f4/src/com/loncaric/xxx/maps/RegisterEventMap.mxml:3]
at com.loncaric.xxx.maps::RegisterEventMap()[/Users/Miran/Documents/Flex Builder 3/ddd_f4/src/com/loncaric/xxx/maps/RegisterEventMap.mxml:9]
at Main/_Main_RegisterEventMap1_i()
at Main()[/Users/Miran/Documents/Flex Builder 3/ddd_f4/src/Main.mxml:5]
at _Main_mx_managers_SystemManager/create()
at mx.managers::SystemManager/initializeTopLevelWindow()[/Users/Miran/Documents/SVN/FlexSDK/frameworks/projects/framework/src/mx/managers/SystemManager.as:3190]
at mx.managers::SystemManager/http://www.adobe.com/2006/flex/mx/internal::docFrameHandler()[/Users/Miran/Documents/SVN/FlexSDK/frameworks/projects/framework/src/mx/managers/SystemManager.as:3066]
at mx.managers::SystemManager/docFrameListener()[/Users/Miran/Documents/SVN/FlexSDK/frameworks/projects/framework/src/mx/managers/SystemManager.as:2918]
EDIT: It seems the problem sticks inside SystemManager which GlobalDispatcher uses.