What is this error?

Assertion failed: !“Pak cannot be unmounted with outstanding requests” [File:D:\build++UE5\Sync\Engine\Source\Runtime\PakFile\Private\IPlatformFilePak.cpp] [Line: 3009]

0x00007ff70b9fc76e PatcherDemo.!UE::Core::Private::Function::TFunctionRefCaller<<lambda_a85b028e20a493eead925c1511528e55>,bool __cdecl(unsigned int)>::Call() []
0x00007ff70b9e864e PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e89d5 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e86e1 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e89d5 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e89d5 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e89d5 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e86e1 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e89d5 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e86e1 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e86e1 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e89d5 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70b9e86e1 PatcherDemo.!SharedPointerInternals::NewIntrusiveReferenceController<1,FFilePackageStoreBackend>() []
0x00007ff70ba3e6f1 PatcherDemo.!FPakPrecacher::Unmount() []
0x00007ff70ba3e3a5 PatcherDemo.!FPakPlatformFile::Unmount() []
0x00007ff70ba087f5 PatcherDemo.!TBaseRawMethodDelegateInstance<0,FPakPlatformFile,bool __cdecl(FString const & __ptr64),FDefaultDelegateUserPolicy>::Execute() []
0x00007ff705164404 PatcherDemo.!FChunkDownloader::UnmountPakFile() []
0x00007ff70515691d PatcherDemo.!FChunkDownloader::Finalize() []
0x00007ff70516088b PatcherDemo.!FChunkDownloader::Shutdown() []
0x00007ff70c4e1d66 PatcherDemo.!UGameEngine::PreExit() []
0x00007ff705134ae9 PatcherDemo.!FEngineLoop::Exit() []
0x00007ff705135a69 PatcherDemo.!GuardedMain() []
0x00007ff705135aba PatcherDemo.!GuardedMainWrapper() []
0x00007ff7051389f6 PatcherDemo.!LaunchWindowsStartup() []
0x00007ff70514a444 PatcherDemo.!WinMain() []
0x00007ff70e49cc2a PatcherDemo.!__scrt_common_main_seh() [D:\a_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl:288]
0x00007ff8445826ad KERNEL32.DLL!UnknownFunction []
0x00007ff845ccaa68 ntdll.dll!UnknownFunction []

when i shut down package game test, this error comes. Why???

I had a same error,do you fixed it?