The `redirect_data->clrdata_len` [is unset in /dlls/ntdll/actctx.c#L4411-4412](https://gitlab.winehq.org/wine/wine/-/blob/master/dlls/ntdll/actctx.c?ref_ty...) when using registration-free COM in C# NET code. Program.cs ```C# //... Guid guid = Guid.Parse("COM clsid"); Type type = Type.GetTypeFromCLSID(guid, true); var instance = Activator.CreateInstance(type)); //... ``` App.manifest ```xml <assembly> <file name="ExampleCOM.dll"> <comClass description="ExampleCOM" progid="ExampleCOM" clsid="{COM clsid}" threadingModel="Free"/> </file> </assembly> ``` The above C# code gets this error on its second line. ```Shell System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt. ``` This is because `len_name` is uninitialized when calling `memcpy(ret_strings, ptr_name, len_name);` in `SxsLookupClrGuid`, which is fixed in this MR. -- v21: add testlib https://gitlab.winehq.org/wine/wine/-/merge_requests/9632