What to use instead of BitStream in Unity 2018.2?

After upgrading to Unity 2018.2, I get

UnityEngine.BitStream’ is obsolete: `The legacy networking system has been removed in Unity 2018.2. Use Unity Multiplayer and NetworkIdentity instead.

What do I use instead of BitStream?

Well that depends. If you actually used the legacy networking system in your project you either have to completely recreate your networking as the new system works entirely different, or your downgrade Unity if you still want to keep using the legacy networking system. You can’t use it in 2018.2+ as it has been completely removed.

If you just looking for a class to serialize data as a bitstream, have a look at the NetworkWriter and NetworkReader classes.