UE 4.24 Build failed. Error: Unknown Error.

Since refactoring some of the insides of how i handle UI transitions in my game, i can no longer build the project. I do not get any errors while compliling the blueprints or when playing in PIE, standalone or launch, but when i try to package i get:


 ...] error C2664: ...]: cannot convert argument 1 from ...] to ...]

I am trying to understand why does this happen. Here is a snippet of the log:



UATHelper: Packaging (Windows (64-bit)): Building 23 actions with 8 processes...
UATHelper: Packaging (Windows (64-bit)): [1/23] Default.rc2
UATHelper: Packaging (Windows (64-bit)): [2/23] SharedPCH.Engine.cpp
UATHelper: Packaging (Windows (64-bit)): [3/23] Module.NativizedAssets.5_of_7.cpp
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Game__pf1489439355.cpp(985): error C2664: 'void AUI_Factory_C__pf1489439355::bpf__AddUIToFactory__pf(const AUI_Factory_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__Sing
lecastDelegate &,const AUI_Factory_C__pf1489439355::FFadeOutThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate &)': cannot convert argument 1 from 'UUI_Game_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate' to 'const AUI_Factory_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate &'
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Game__pf1489439355.cpp(985): note: Reason: cannot convert from 'UUI_Game_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate' to 'const AUI_Factory_C__pf148
9439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate'
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Game__pf1489439355.cpp(985): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Factory__pf1489439355.cpp(509): note: see declaration of 'AUI_Factory_C__pf1489439355::bpf__AddUIToFactory__pf'
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Loading__pf1489439355.cpp(1561): error C2664: 'void AUI_Factory_C__pf1489439355::bpf__AddUIToFactory__pf(const AUI_Factory_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__
SinglecastDelegate &,const AUI_Factory_C__pf1489439355::FFadeOutThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate &)': cannot convert argument 1 from 'UUI_Loading_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate' to 'const AUI_Factory_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate &'
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Loading__pf1489439355.cpp(1561): note: Reason: cannot convert from 'UUI_Loading_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate' to 'const AUI_Factory_C
__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate'
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Loading__pf1489439355.cpp(1561): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_Factory__pf1489439355.cpp(509): note: see declaration of 'AUI_Factory_C__pf1489439355::bpf__AddUIToFactory__pf'
UATHelper: Packaging (Windows (64-bit)): [4/23] Module.NativizedAssets.6_of_7.cpp
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_PauseMenu__pf1489439355.cpp(8889): error C2664: 'void AUI_Factory_C__pf1489439355::bpf__AddUIToFactory__pf(const AUI_Factory_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf
__SinglecastDelegate &,const AUI_Factory_C__pf1489439355::FFadeOutThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate &)': cannot convert argument 1 from 'UUI_PauseMenu_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate' to 'const AUI_Factory_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate &
'
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_PauseMenu__pf1489439355.cpp(8889): note: Reason: cannot convert from 'UUI_PauseMenu_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate' to 'const AUI_Facto
ry_C__pf1489439355::FFadeInThisWidgetDisp__pf__UI_Factory_C__pf__SinglecastDelegate'
UATHelper: Packaging (Windows (64-bit)): E:/Paradox/Paradox_4.24/Intermediate/Plugins/NativizedAssets/Windows/Game/Source/NativizedAssets/Private/UI_PauseMenu__pf1489439355.cpp(8889): note: No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called
UATHelper: Packaging (Windows (64-bit)): E:\Paradox\Paradox_4.24\Intermediate\Plugins\NativizedAssets\Windows\Game\Source\NativizedAssets\Public\UI_Factory__pf1489439355.h(45): note: see declaration of 'AUI_Factory_C__pf1489439355::bpf__AddUIToFactory__pf'
UATHelper: Packaging (Windows (64-bit)): [5/23] Module.NativizedAssets.gen.4_of_6.cpp
UATHelper: Packaging (Windows (64-bit)): [6/23] Module.NativizedAssets.7_of_7.cpp
UATHelper: Packaging (Windows (64-bit)): [7/23] Module.NativizedAssets.1_of_7.cpp
UATHelper: Packaging (Windows (64-bit)): [8/23] Module.NativizedAssets.2_of_7.cpp
UATHelper: Packaging (Windows (64-bit)): [9/23] PDXPatronList.cpp
UATHelper: Packaging (Windows (64-bit)): [10/23] Module.NativizedAssets.gen.6_of_6.cpp
UATHelper: Packaging (Windows (64-bit)): [11/23] Paradox.cpp
UATHelper: Packaging (Windows (64-bit)): [12/23] PDXInputSettings.cpp
UATHelper: Packaging (Windows (64-bit)): [13/23] Module.NativizedAssets.gen.1_of_6.cpp
UATHelper: Packaging (Windows (64-bit)): [14/23] Paradox.init.gen.cpp
UATHelper: Packaging (Windows (64-bit)): [15/23] PDXPatronList.gen.cpp
UATHelper: Packaging (Windows (64-bit)): [16/23] PDXInputSettings.gen.cpp
UATHelper: Packaging (Windows (64-bit)): [17/23] Module.NativizedAssets.gen.3_of_6.cpp
UATHelper: Packaging (Windows (64-bit)): [18/23] Module.NativizedAssets.gen.2_of_6.cpp
UATHelper: Packaging (Windows (64-bit)): [19/23] Module.NativizedAssets.4_of_7.cpp
UATHelper: Packaging (Windows (64-bit)): [20/23] Module.NativizedAssets.3_of_7.cpp
UATHelper: Packaging (Windows (64-bit)): [21/23] Module.NativizedAssets.gen.5_of_6.cpp
UATHelper: Packaging (Windows (64-bit)): Took 113,0010251s to run UnrealBuildTool.exe, ExitCode=5
UATHelper: Packaging (Windows (64-bit)): UnrealBuildTool failed. See log for more details. (C:\Users\Guest2\AppData\Roaming\Unreal Engine\AutomationTool\Logs\C+Program+Files+Epic+Games+UE_4.24\UBT-Paradox-Win64-Shipping_2.txt)
UATHelper: Packaging (Windows (64-bit)): AutomationTool exiting with ExitCode=5 (5)
UATHelper: Packaging (Windows (64-bit)): BUILD FAILED
PackagingResults: Error: Unknown Error


After poking around, i discovered that (if i understand correctly) when nativizing, actor and level delegate binds are by default constant, but UI single cast delegates are not, and as such, I can not use a function in the actor to handle binding delegates, the binds need to be called directly from the blueprints that handle the event.