Virtual static method 'Serialize' is not implemented on type

[vanhaodev]

[harayuu9]

I encountered the same situation, but since this issue lacks sufficient explanation, I can’t be certain it refers to the same thing. Nonetheless, I’ll describe the probable situation and the approach to address it. The issue occurs when a class library containing a MessagePackable targeting .NET Standard 2.1 is referenced in an application created with .NET 7 or 8. This is caused by MemoryPack changing the generated code to match the .NET version during the code generation process. Therefore, it’s necessary to align the .NET versions of the class library and the application. Simply raising the version of the library might not suffice, especially if it needs to be simultaneously referenced by environments like Unity. However, since multiple target platforms can be specified as shown below, it’s advisable to configure it this way:

<TargetFrameworks>net8.0;netstandard2.1</TargetFrameworks>