Earlier today I learned about the cache and run workflow option but now as I am trying to use it the option is grayed out in the menu and won't let me select it. Why is that?
That may be either because you are attempting to cache on a tool that has multiple outputs.
Or because your workflow joins on to itself downstream.
Try caching at the end of your workflow on something simple like a Select Tool with single output anchor.
@CherieACI
Just add to @PhilipMannering , below the a few things we need to know about Cache.