Addressables load in Editor, but not in Build

I am getting an error that says failed to load my addressable.

This is the first build I've done since adding addressables to my project, so my assumption is that I missed a critical step in setup to make addressables work in build, but I am not sure what or where.

Googling the problem, I see reference to setting Editor to Packed Mode, but this is done in the "Addressables" window, which doesn't appear to exist anymore in latest? At least I cannot find it.

How can I resolve this? What further info do you need to help me resolve this?

 

First thing to check, are you making sure to build your addressables before building your game?