Deserializing error, possibly related to enums

Replaying data from a data store has generally been very useful, and this is the first time I have had a type that was not able to be deserialized. It looks like the error is related to an enum nested inside of the class. What is the best way to handle this? Just move the enum to outside the class? Do I need to define a deserializer? Or maybe I need to store with primitive types and reconstruct the type after deserializing?

System.AggregateException
HResult=0x80131500
Message=Pipeline 'default' was terminated because of one or more unexpected errors (Failed to create a deserializer for type System.Collections.Generic.EnumEqualityComparer1[[EmotionRepresentation.EmotionCategory+Category, EmotionRepresentation, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 because no type was registered for this name and the source type System.Collections.Generic.EnumEqualityComparer1[[EmotionRepresentation.EmotionCategory+Category, EmotionRepresentation, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 could not be found. Add a reference to the assembly containing this type, or register an alternate type for this name.)
Source=Microsoft.Psi
StackTrace:
at Microsoft.Psi.Pipeline.ThrowIfError()
at MainCore.ReasonerTest.Main(String[] args) in C:\linux\repos\temp\psiAssistiveAgent\MainCore\ReasonerTest.cs:line 44

Inner Exception 1:
SerializationException: Failed to create a deserializer for type System.Collections.Generic.EnumEqualityComparer1[[EmotionRepresentation.EmotionCategory+Category, EmotionRepresentation, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 because no type was registered for this name and the source type System.Collections.Generic.EnumEqualityComparer1[[EmotionRepresentation.EmotionCategory+Category, EmotionRepresentation, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089 could not be found. Add a reference to the assembly containing this type, or register an alternate type for this name.

Start at MainCore/ReasonerTest.cs line 44 and reproduce the replay failure using the nested enum and the reported EnumEqualityComparer type. Trace the deserialization error to determine whether the issue is type registration, nested enum handling, or collection reconstruction. Done means identifying the supported handling and documenting or testing the resulting resolution.