Invalid generic arguments exceptions upon updating to Unity 2017.1 from the latest Unity 5

[Former user]

I have been trying in vain to figure out what causes this issue. Upon upgrading my project to 2017.1 (with a backup of course) and inspecting some prefabs many instances of the below error popped out. Sometimes continuously. Generally, these errors appear when inspector fields are being drawn.

Unfortunately, all nullable fields of prefabs/GameObjects serialized with Odin were set to null upon opening the project in Unity 2017. After refilling the null fields with a new object they would eventually get reset to null after poking around in other areas of the inspector and receiving some reports of the below error.

I cannot reproduce this in a clean project.

Unity Version: 2017.1.0f3

The traceback shown for every instance of the error is:

ArgumentException: Invalid generic arguments Parameter name: typeArguments System.RuntimeType.MakeGenericType (System.Type[] instantiation) (at /Users/builduser/buildslave/mono/build/mcs/class/referencesource/mscorlib/system/rttype.cs:4272) Sirenix.Serialization.Serializer.Create (System.Type type) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Serializers/Serializer.cs:133) Sirenix.Serialization.Serializer.Get (System.Type type) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Serializers/Serializer.cs:94) Sirenix.Serialization.Emitted.StartupFormatterHelper..cctor () (at <244b182f5eb64a35b2a827886c70d946>:0) Rethrow as TypeInitializationException: The type initializer for 'Sirenix.Serialization.Emitted.StartupFormatterHelper' threw an exception. <0x00000 + 0x00000> <unknown method> (wrapper dynamic-method) System.Object:Dynamic_Write_Startup (Startup&,Sirenix.Serialization.IDataWriter) Sirenix.Serialization.FormatterEmitter+EmittedFormatter1[T].WriteDataEntries (T& value, Sirenix.Serialization.IDataWriter writer) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Formatters/FormatterEmitter.cs:63) Sirenix.Serialization.EasyBaseFormatter1[T].SerializeImplementation (T& value, Sirenix.Serialization.IDataWriter writer) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Formatters/EasyBaseFormatter.cs:47) Sirenix.Serialization.BaseFormatter1[T].Serialize (T value, Sirenix.Serialization.IDataWriter writer) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Formatters/BaseFormatter.cs:244) UnityEngine.Debug:LogException(Exception) Sirenix.Serialization.CustomLogger:LogException(Exception) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization.Config/CustomLogger.cs:61) Sirenix.Serialization.DebugContext:LogException(Exception) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Misc/SerializationConfig.cs:222) Sirenix.Serialization.BaseFormatter1:Serialize(Startup, IDataWriter) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Formatters/BaseFormatter.cs:248) Sirenix.Serialization.BaseFormatter1:Sirenix.Serialization.IFormatter.Serialize(Object, IDataWriter) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Formatters/BaseFormatter.cs:113) Sirenix.Serialization.ComplexTypeSerializer1:WriteValue(String, Startup, IDataWriter) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Serializers/ComplexTypeSerializer.cs:492) Sirenix.Serialization.Serializer`1:WriteValueWeak(String, Object, IDataWriter) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Serializers/Serializer.cs:187) Sirenix.Serialization.UnitySerializationUtility:SerializeUnityObject(Object, IDataWriter, Boolean) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Utilities/UnitySerializationUtility.cs:717) Sirenix.Serialization.UnitySerializationUtility:SerializeUnityObject(Object, SerializationData&, Boolean, SerializationContext) (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Utilities/UnitySerializationUtility.cs:420) Sirenix.OdinInspector.SerializedMonoBehaviour:UnityEngine.ISerializationCallbackReceiver.OnBeforeSerialize() (at C:/Users/Bjarke/Desktop/Projects/Sirenix/Sirenix Solution/Sirenix.Serialization/Unity Integration/SerializedMonoBehaviour.cs:32)

[Odin User]

Same person as above.

Found out this only happens after changing the Scripting Runtime Version to 4.6 AFTER opening the project in Unity 2017.1. Everything seems to be fine before changing that.

[Odin User]

Changing the runtime version back to 3.5 and reopening the project retains all serialized information as if I never switched to 4.6 in the first place.

[Odin User]

With the version set to 4.6:

Reimporting all assets causes Unity to crash and subsequently crash each time the same project is opened afterward.

[Tor Esa Vestergaard]

The crash is a known bug that's caused by Unity itself when it imports assemblies. We've communicated with Unity and supposedly they're going to patch it very soon.

The other bug is a new one - we'll give that a prompt look. Thanks for reporting it! The new 4.6 scripting backend is proving to be quite temperamental.

[Tor Esa Vestergaard]

I've identified and fixed the other issue with the exceptions you're getting - it seems that some generic class constraints function differently in .NET 4.6. This happens when Odin is preparing to serialize or deserialize an enum value (or something containing an enum), and throws exceptions in a rather unexpected part of the system, thus causing a lot of lost values.

[Tor Esa Vestergaard]

If getting a fix for this is a very high priority for you, you can send me a mail at [e-mail] with your invoice number, and I'll send you a build containing the fix.

[Odin User]

I'm not in much of a rush. Mostly just looking forward to auto property initializers. Best of luck with the next patch!