Unloading 0 Unused Serialized files (Serialized files now loaded: 0)

When running my game on android, it now takes an extremely long time to load new scenes.

I looked at the logcat while the game was running, and I see this entry 1000’s of times:
Unloading 0 Unused Serialized files (Serialized files now loaded: 0)

It finally stops after multiple minutes depending on how complex the previous scene was.

This started happening when I updated to the latest version of Unity. No code changed, and before the update, the scenes all loaded instantly on android, even on low end devices.

I’m in desperate need of help.

We have the same issue in Unity 5.5.2p4.
@penneyworth1 Did you managed to do something with that problem?