I get this exception on boot. For me it seems to happen around the time IAP is initialized.
InvalidOperationException: Package registration has been locked. Make sure to register service packages in[RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.BeforeSceneLoad)].
at Unity.Services.Core.Internal.LockedPackageRegistry.RegisterPackage[TPackage] (TPackage package) [0x00000] in <00000000000000000000000000000000>:0
at Unity.Services.Core.Internal.CoreRegistry.RegisterPackage[TPackage] (TPackage package) [0x00000] in
It doesn’t seem to cause any issues with my game, but it is very annoying.