I know I'm trying to do the equivalent of Economic Analysis without having done Calculus, but I've gotten this far and just need to know how to correctly append the error message to :

AND(CloseDate < TODAY(), NOT(IsClosed))

Is there a correct modifier to put before the phrase: "Hey McFly, unless you are planning to go back in time, please update your close date"?
Is it supposed to be part of the formula, or on a separate line?

I'm working with adding fields and then getting them into my compact layout. I've set up Account Name and Account Owner the same way as Lookup Relationship and Text fields.  However the challenge only picks up that one of them is not showing in my Compact Layout.  When I look at the page layouts, you'll see that both the Account Name and Account Owner fields are grayed out.  Does this have anything to do with it?  Or is that another issue altogether?