Issue

Due to a limitation with Unity’s serialization system, embedded value providers cannot be serialized directly as part of prefab assets.

Solution 1: Create Asset

You can get around this limitation by adding the [CreateAssetMenu] attribute to your value provider, and creating assets to back them.

You can then drag-and-drop the value provider assets into the Init argument fields on your prefab, and they can be serialized.

Another way to bypass the limitation is to the convert the embedded value providers into sub-assets of the prefab asset.

You can do this by right-clicking an embedded value provider on a prefab instance in the Inspector, and selecting ‘Make Sub-Asset of Prefab‘.

You can reverse the process by right-clicking the value provider in the prefab instance again, and selecting ‘Embed Into Prefab Instance‘.