Bug IL2CPP error on Building for Windows

Unity 2021.3.11. I cannot build for Windows.... Linux/Mac/Nintendo Switch is working as expected. What I can try to fix it?

Code (CSharp):

1. Building Library\Bee\artifacts\WinPlayerBuildProgram\t2s8s\cc18_0_vm6.lump.obj failed with output:
2. xbo0_vm6.lump.cpp
3. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(71): error C2039: 'hash_compare': is not a member of 'stdext'
4. C:\Program Files\Microsoft Visual Studio\2022\Enterprise\VC\Tools\MSVC\14.34.31931\include\iterator(1426): note: see declaration of 'stdext'
5. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(71): error C2065: 'hash_compare': undeclared identifier
6. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(71): error C2275: 'Key': expected an expression instead of a type
7. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(38): error C2976: 'Il2CppReaderWriterLockedHashMap': too few template arguments
8. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
9. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(38): error C2974: 'Il2CppReaderWriterLockedHashMap': invalid template argument for 'HashFcn', type expected
10. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
11. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(38): error C2955: 'Il2CppReaderWriterLockedHashMap': use of class template requires template argument list
12. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
13. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(47): error C2955: 'Il2CppReaderWriterLockedHashMap': use of class template requires template argument list
14. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
15. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): error C2662: 'bool Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::TryGet(const Il2CppHashMap<Key,T,HashFcn,EqualKey,Alloc>::key_type &,T *)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc> &'
16. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>'
17. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): note: Conversion requires a second user-defined-conversion operator or constructor
18. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(90): note: see declaration of 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::TryGet'
19. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(385): note: while trying to match the argument list '(Il2CppClass *, Il2CppClass **)'
20. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): error C2662: 'bool Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::Add(const Il2CppHashMap<Key,T,HashFcn,EqualKey,Alloc>::key_type &,const T &)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc> &'
21. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>'
22. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): note: Conversion requires a second user-defined-conversion operator or constructor
23. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(102): note: see declaration of 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::Add'
24. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(438): note: while trying to match the argument list '(Il2CppClass *, Il2CppClass *)'
25. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): error C2955: 'Il2CppReaderWriterLockedHashMap': use of class template requires template argument list
26. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(75): note: see declaration of 'Il2CppReaderWriterLockedHashMap'
27. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): error C2662: 'Il2CppHashMap<Key,T,HashFcn,EqualKey,Alloc>::iterator Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::UnlockedBegin(void)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc> &'
28. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>'
29. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): note: Conversion requires a second user-defined-conversion operator or constructor
30. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(121): note: see declaration of 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::UnlockedBegin'
31. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): note: while trying to match the argument list '()'
32. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): error C2662: 'Il2CppHashMap<Key,T,HashFcn,EqualKey,Alloc>::iterator Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::UnlockedEnd(void)': cannot convert 'this' pointer from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc> &'
33. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): note: Reason: cannot convert from 'PointerTypeMap' to 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>'
34. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): note: Conversion requires a second user-defined-conversion operator or constructor
35. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\utils\Il2CppHashMap.h(127): note: see declaration of 'Il2CppReaderWriterLockedHashMap<Key,T,HashFcn,EqualKey,Alloc>::UnlockedEnd'
36. C:\Unity\2021.3.11f1\Editor\Data\il2cpp\libil2cpp\vm\MetadataCache.cpp(1135): note: while trying to match the argument list '()'
37. UnityEngine.GUIUtility:ProcessEvent (int,intptr,bool&)

 

I've just run into this same error myself.
In my case, it was because I was running Visual Studio 2022 (17.4.0 Preview 4.0)..
Once I removed it and installed Visual Studio 2022 (17.3.6) I was able to build for Windows using the ILCPP scripting backend without issue.
This is rather irksome though since I was using the preview version to access .net 7 and the associated MAUI components so it would be appreciated to have the ability to select which version of Visual Studio we'd like to use as the compiler.

 

This also affects Unity 2020, UWP builds & from the looks of it, Microsoft is not going to revert the change.

 

For those who are receiving this error but want to keep on using their current version of Visual Studio, Microsoft has suggested adding the following environmental variable and then restart Windows:

Variable Name: _CL_
Variable Value: /D_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS

I've tested this on my system using Unity 2022.1.20f1 and Visual Studio 2022 (17.4.0 Preview 5.0) and it does work.

 

Life Saver!

 

Good news, that bug was fixed on the latest version of Unity:
https://forum.unity.com/threads/wor...-il2cpp-with-visual-studio-2022-17-4.1355570/

 

Oh my ....
Searching in the deepest hells of the internet for this.
Thank you so much for posting this. This is genius

 

Really life saver. Thanks for this

 

Thanks so much. It works on my project too.

 

untiy 2021.3.4f1c1
visual Studio version 2019
I tried all of the above without success, but after I removed vs C++ desktop development, I reinstalled it and everything was back to normal.