I met a exception which says:
System.MissingMethodException: Method not found: ‘UnityEditor.PackageManager.Client.List’.
at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[ ],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[ ] parameters, System.Globalization.CultureInfo culture) [0x000d0] in /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222
UnityEditor.EditorAssemblies:ProcessInitializeOnLoadAttributes()
What may cause such a problem? How to fix it? btw, I copied some asset from one of my 2018.1 project and I think it might be a explanation?