Due to this, MDIL fails to properly process structs from UnityEngine.dll used as generic parameters, thus causing InvalidCastExceptions when casting between such types.

To reproduce:
1. Open attached project. It contains the DOTween library. There is also a script that tries to cast a ITweenPlugin as an ABSTweenPlugin<Vector3, Vector3, VectorOptions>
2. Build & run for WP8.1
3. Notice the text on screen - it says "Tween 2", meaning that the cast failed (returned null)

Deploying the same solution through visual studio will output "Tween 1", meaning that the cast was successful

Does not reproduce with WP8