Posting this since I spend 3 hours on this silliness and thought I'd help someone else if it ever comes up again.
#1 Have .php file, works fine in browsers.
#2 Have AJAX on send...tag, data, post...updates the database.
***Everything works and yet...still triggers Error*** (error in construct and not triggering next events*)
Could find nothing on C2 forums that helped figure it out...(didn't know what the problem was, so hard to find a solution)
Finally I went to the browser developer tools to see if anything was there.
On Mozilla: Developer, Console
Scrolled down to see:
Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://www.***etc., etc.com?call=1234 (Reason: CORS header â€˜Access-Control-Allow-Originâ€™ missing).
After 5 minutes...the "L"s in Allow were "1"s... (no clue how that happened on a copy/paste), hope this might help others to self identify AJAX issues.