Does anyone else have trouble locked out of HBOMax? Error code is "your HBOMax promotional subscription has expired"

Nope. Is HBO Max currently active on your account? Check by going to DIRECTV.com, logging in with your online account, and seeing your current channels under My Programming.

If the app is showing this error, it could be a technical issue on HBO MAx’s side. Are you sure you are logging in with TV PROVIDER AND DIRECTV? If you choose DIRECTV STREAM it will NOT work as DIRECTV satellite and DIRECTV STREAM are two different services.

Yep, I'm having the exact same issue. It seems to be a "DirecTV and AT&T account not talking to each other issue". I'm 10 days and counting, and Support haven't got a clue. 

Total BS!  I've spent hours trying to figure it out.  Spent hours on phone and getting bounced back and forth from ATT to DirecTV and back.  Somebody needs to pull their head out of their collective a$$es.  I'm  spending a ton of money with DirecTV.

How to resolve: Raise a complaint on BBB.org - this alerts the Office of the President at DirecTV. Within a couple of weeks, and a few calls, the US-based tech team resolved the issue. According to the person that I was assigned, the off-shore teams don't have a clue, or the ability, to fix it. Good luck.

Thanks pal.  Just completed the complaint form on BBB.org.  We'll see what happens.  

Well, I followed AndyWarner71's advice and got a call from the office of the President at DirecTV.  She worked with me for a few minutes then said she would get with the Engineers and get back to me either tomorrow or Friday.  I told her that I wasn't the 1st person with this problem

Thanks again Andy.

Lady at DirecTV called and it's fixed.  I now have HBOMax again.

Another shoutout to AndyWarner 71 without whose advice this prolly would not have been possible.  

Perfect! Glad it all got fixed, and am happy to have been a small part of you getting a resolution.

More than a small part.  Prolly would never have happened without your info.