After update to UE 5.6 build banks crashed engine

Unreal Engine
1

After upgrading to the new version of fmod studio and ue 5.6, I started getting constant crashes of the engine, which starts to strain and interfere with my work very much.

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Assertion failed: Pair != nullptr [File:D:\build++UE5\Sync\Engine\Source\Runtime\Core\Public\Containers\Map.h] [Line: 729]

UnrealEditor_Core
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_Engine
UnrealEditor_FMODStudioEditor!FFMODAssetBuilder::BuildBankLookup() [D:\Games\Race_project\race_project_main\Plugins\FMODStudio\Source\FMODStudioEditor\Private\FMODAssetBuilder.cpp:359]
UnrealEditor_FMODStudioEditor!FFMODAssetBuilder::ProcessBanks() [D:\Games\Race_project\race_project_main\Plugins\FMODStudio\Source\FMODStudioEditor\Private\FMODAssetBuilder.cpp:50]
UnrealEditor_FMODStudioEditor!FFMODStudioEditorModule::ReloadBanks() [D:\Games\Race_project\race_project_main\Plugins\FMODStudio\Source\FMODStudioEditor\Private\FMODStudioEditorModule.cpp:1245]
UnrealEditor_FMODStudioEditor!FFMODStudioEditorModule::ProcessBanks() [D:\Games\Race_project\race_project_main\Plugins\FMODStudio\Source\FMODStudioEditor\Private\FMODStudioEditorModule.cpp:388]
UnrealEditor_FMODStudioEditor!TBaseRawMethodDelegateInstance<0,FFMODStudioEditorModule,void __cdecl(void),FDefaultDelegateUserPolicy>::ExecuteIfSafe() [E:\UE_5.6\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:547]
UnrealEditor_FMODStudioEditor!FFMODBankUpdateNotifier::Update() [D:\Games\Race_project\race_project_main\Plugins\FMODStudio\Source\FMODStudioEditor\Private\FMODBankUpdateNotifier.cpp:42]
UnrealEditor_FMODStudioEditor!FFMODStudioEditorModule::Tick() [D:\Games\Race_project\race_project_main\Plugins\FMODStudio\Source\FMODStudioEditor\Private\FMODStudioEditorModule.cpp:1084]
UnrealEditor_FMODStudioEditor!TBaseRawMethodDelegateInstance<0,FFMODStudioEditorModule,bool __cdecl(float),FDefaultDelegateUserPolicy>::Execute() [E:\UE_5.6\Engine\Source\Runtime\Core\Public\Delegates\DelegateInstancesImpl.h:531]
UnrealEditor_Core
UnrealEditor_Core
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
UnrealEditor
kernel32
ntdll

2

Hi,

Thank you for bringing this to our attention.

Could I get any reproduction steps that consistently cause a crash?

3

Hi,

Thank you for the quick response.

Here are the steps that consistently lead to a crash on my end:
1. I upgraded Unreal Engine from 5.4 to 5.6.
2. I also updated FMOD Studio to the version required by the plugin.
3. I recompiled the project — the build completed successfully without errors.
4. With both Unreal Engine and FMOD Studio open, I started working with audio as usual.
5. After making changes in FMOD Studio, I clicked the Build button to rebuild the banks.
6. Each time I do this, Unreal Engine crashes immediately after pressing Build in FMOD Studio.
7. Despite the crash, the banks are built successfully. However, the crash happens consistently every time I build.

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