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Hi, I got some problem when I add Photon3DotNet.dll to Plugins folder

dll version: Photon-OnPremise-Server-SDK_v4-0-29-11263
Unity version: Unity 2019.4.20f1c1 Personal
Unity Api Compatibility Level: .NET Standard 2.0(I try to use .NET 4.x, same problem)

Thanks!