Just open the attached unity project with unity 2020, and you'll get the error: Code (CSharp): Assembly 'Assets/System.Memory.dll' will not be loaded due to errors: System.Memory references strong named System.Buffers, versions has to match. Assembly references: 22.214.171.124 Found in project: 126.96.36.199. I generated the DLL dependency tree with a vanilla csproj and let nuget autoresolve them so i know for sure these DLLs work with each other. They work in unity 2018 and 2019, but it doesn't like it in 2020. I reported the bug literally months ago and got a no-repro response, yet i can reproduce it across several OSes and Unity 2020.1.x alphas and betas.