Wwise integration: The type or namespace name 'AK' could not be found.

I’ve been using Wwise in Unity and it worked great, but I left my project alone for a while, I came back and now code that compiled before no longer compiles.

Here’s some of the lines that give me the problem:

    public AK.Wwise.Event m_playStrategyMusic;
    public AK.Wwise.Event m_stopStrategyMusic;
    public AK.Wwise.Event m_playStartGameButton;

I’m getting this error: The type or namespace name ‘AK’ could not be found (are you missing a using directive or an assembly reference?)

It was working fine last time I used it a few months ago, I’m using Unity 2019.2.3f1, Wwise 2019.1.6.7110

I ran into this same issue–I solved it by adding all the Assembly Definition References for Wwise in the Project Assembly File.

Here is more info here: Unity - Manual: Assembly Definitions