Is this a Field Maps or ArcGIS Online Error?

[RTPL_AU]

I am having trouble figuring out what this error is. 
That said - is it an error? I see a tick mark.  

[RTPL_AU]

It's an error.  The giveaway hiding in the top left:

Nr2 (no, you can't scroll down to unhide them):

The whole offline areas packaging window falls over. 

Joaquin Phoenix in the House!!!

Now I wonder. Should I lodge a case, Idea, or give documentation feedback?

[DanielFox1]

Hi @RTPL_AU 

I recommend you log a support case with your distributor and outline your workflow to see if this can be reproduced. Very strange behaviour for sure.

[RTPL_AU]

@DanielFox1 

I just write it down to the Offline Areas process being buggy. Too many variables involved and it is too intermittent to know if it is me or Esri. I know where my money is as I'm just following one of the simplest point & click workflows in AGOL and the same data has been used before. 
I've never seen this behaviour before and probably never will again.

I've lodged an Idea to have AGOL error messages be more verbose and to give us access to logs of some sort. Without some visibility into the process both the distributor and myself are fishing for cornflakes made from corn..... it exists but chances are you'll have to find it in the gluten free isle....

As with so many things Esri, we just try doing the same thing another two times. Chances are, it will just start working again; which it did.