Hello!

I actually had the same issue with some clients.  For me, the reason was because the EFTPS password expired (I think that QuickBooks is forcing people to regularly update their EFTPS password, maybe?)

So, I just logged in on EFTPS, updated the password, then resubmitted and it went through successfully. 

I hope that helps!

I also really hope that QuickBooks fixes this issue with the E-Payments for Employers that used to E-Pay Maryland Unemployment liability... This has been an issue for over a month, now.