I have a problem similar to the posters in several other recent threads. It had been a little less than a week since updating all our accounts and paying bills at which time everything worked perfectly. This morning, when updating all our accounts I received the CC-800 error on our Synchronicity charge account and one of our Discover accounts.
We have only one Synchronicity account (i.e., Amazon Prime) which does not have a symbol next to it and the One Step Update downloaded new transactions even though I received the CC-800 error. I receive the error whenever I do Update Now.
We have three Discover accounts and the one with the error appears to be our Discover banking account. The two Discover charge accounts appear to have updated fine although there weren't new transactions to download. I receive the error on the banking account whenever I do Update Now, but I can perform Update Now on the credit card accounts without issue. The Discover banking account has a symbol next to it.
The only thing I know changed between last week and now is a Quicken Classic update (R52.33 27.1.52.33). I haven't tried any remedial action beyond stopping/starting Quicken.
I haven't tried any remedial action hoping for a quick resolution here.