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Adding to multi-cast delegate causing crash

I have declared a multicast delegate like so:

 FDelegateType MyDelegate;

but when I try to add a function to this delegate

 MyDelegate.AddUObject(this, &SomeClass::SomeFunction);

it causes Unreal to crash with the following error:

 Access violation - code c0000005 (first/second chance not available)
 UE4Editor_Unreal!FMulticastDelegateBase<FWeakObjectPtr>::CompactInvocationList() [c:\program files\epic games\ue_4.18\engine\source\runtime\core\public\delegates\multicastdelegatebase.h:159]
 UE4Editor_Unreal!FMulticastDelegateBase<FWeakObjectPtr>::AddInternal() [c:\program files\epic games\ue_4.18\engine\source\runtime\core\public\delegates\multicastdelegatebase.h:146]
 UE4Editor_Unreal!TBaseMulticastDelegate<void>::AddUObject<UHUDScoreBar>() [c:\program files\epic games\ue_4.18\engine\source\runtime\core\public\delegates\delegatesignatureimpl.inl:837]

Specifically, the variable InvocationListLockCount (a mutable int) in MulticastDelegateBase.h has a null value.

It seems as though the delegate has not been initialized, but I am unsure why.

Any help would be appreciated.

Product Version: UE 4.18
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asked Mar 28 '18 at 09:36 AM in C++ Programming

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avatar image GigasightMedia Mar 29 '18 at 11:41 AM

Where/when are you binding the delegate?

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answered Mar 29 '18 at 02:51 PM

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