UE4 crashes due to corrupted multicast method

Hello.

This is happening before and after upgrading to 4.21, on v4.20 application crashed without further message, on v4.21 application freezes out.

What “I think” (not sure) I did to make this fail:
-Perhaps it was related to a merge, or a file restore, not sure, but after some movements, a particular multicast method was called twice everytime from the server, even if my execution was clearly calling it just once. All clients received multicast on the same instance twice.

I figured out that something was wrong in the delegate of the multicast event, perhaps behind scenes on the blueprint there was a repeated delegate assignment, which I fixed (after a lot of debug) by erasing this multicast method, and creating another one exactly the same with different name. Inside does the same, and server calls it the same. It started working after that.

But then, after closing and reopening game, it started crashing everytime i try to call this new multicast method, and in logs I was able to read what I pasted below.:

How can I solve this issue? i`m stuck here because of this, nothing I can do in blueprints at least.

Thanks in advance.

LOG:

[2019.03.26-03.55.37:142][710]LogSlate: FSceneViewport::OnFocusLost() reason 0
[2019.03.26-03.55.49:639][411]LogWindows: Error: === Critical error: ===
[2019.03.26-03.55.49:639][411]LogWindows: Error: 
[2019.03.26-03.55.49:639][411]LogWindows: Error: Fatal error!
[2019.03.26-03.55.49:639][411]LogWindows: Error: 
[2019.03.26-03.55.49:639][411]LogWindows: Error: Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0x000002da
[2019.03.26-03.55.49:640][411]LogWindows: Error: 
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6f4a514 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6f3d292 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6f498af UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6378b08 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd0a0183 UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd079e1d UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd0a03ff UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd079e1d UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd09dcbc UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd0a03ff UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd079e1d UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd0a03ff UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd079e1d UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd0a03ff UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacce74b14 UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffacd09f998 UE4Editor-CoreUObject.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab63b3853 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab69a73b1 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab69a1d92 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6992b8a UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab69a2b3e UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab69a83ac UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab69a689e UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab69a7fe8 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6f4eb5a UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6f4fe18 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffa94970e1a UE4Editor-OnlineSubsystemUtils.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6f1e5af UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab62c1a53 UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffab6d761fb UE4Editor-Engine.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffaad981f95 UE4Editor-UnrealEd.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffaae2a2216 UE4Editor-UnrealEd.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ff78aa26225 UE4Editor.exe!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ff78aa3596c UE4Editor.exe!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ff78aa359ea UE4Editor.exe!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ff78aa448da UE4Editor.exe!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ff78aa4659a UE4Editor.exe!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffb06233dc4 KERNEL32.DLL!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: [Callstack] 0x00007ffb07fe3691 ntdll.dll!UnknownFunction []
[2019.03.26-03.55.49:640][411]LogWindows: Error: 
[2019.03.26-03.55.49:653][411]LogExit: Executing StaticShutdownAfterError
[2019.03.26-03.55.49:657][411]LogWindows: FPlatformMisc::RequestExit(1)
[2019.03.26-03.55.49:659][411]Log file closed, 03/26/19 00:55:49

Hello,

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Thanks