one step update fails on all accounts two separate files- Screen flashes nothing updates

Sometimes version updates of Quicken do not install correctly or completely. Maybe that is what happened and is causing the issue you are seeing?

You might want to try downloading and installing the Manual Patch Update file from https://www.quicken.com/support/update-and-patch-20182019-release-quicken-windows-subscription-product/ . You can simply install this right over the existing installation. This will often fix this type of issue.

If that doesn't fix it I would uninstall Quicken. Then download a fresh copy of Quicken from the online Quicken account or from https://www.quicken.com/support/how-do-i-download-quicken-quickencom-after-i-buy-it/ and then install it.

Post back here whether or not either of these things resolved the issue for you.