Concurrent for Alert completing in Error

Hi...I'm trying to create an Alert for the first time so sorry if this is not the correct space to be asking this. 

I've created the Alert and did the necessary action to trigger the alert, expecting to receive an email, but I didn't receive anything. 

I looked in my concurrent requests and there are 3 requests there, all erred, but there isn't any error information provided.  I'm not really sure what/where to go from there?

The alert is to send an email to the PO Requester once the PO is approved. 

I was following this note to set it up...my sql is a little different but is the same idea, and when I clicked Verify it came back OK.