If your bank recently required you to reauthorize your checking account and/or your bank has changed from "Direct Connect" to either "Express Web Connect" or "Express Web Connect+" you can no longer use Online Bill Pay direct to the bank or Quicken Bill Manager's Quick Pay function. The bank no longer supports this function through Quicken.
You have these alternatives (in no particular order of preference):
I've been using a variation of method #3 for decades, since before the Internet and dial-up were even introduced. It's easy to get used to this process. And I have yet to miss a single payment.
While the banks may be happy that users are forced to use them (mostly) their bill paying/tracking process is the pits!
Don't forget to complain to the banks. Setting up automatic recurring debits at the billers' websites is a short one-time process. Once that's done, entering a scheduled reminder transaction in Quicken every month when you receive the next bill or statement is a matter of seconds.