Quicken crashes on startup after latest update

3 very frustrating hours into trying to get quicken to start again after an update this morning. I've tried all the suggested remedies, including mondo patch QW27.1.41.9MPatch.EXE, uninstall/reinstall, deleting install directory, disabling firewall, starting without loading a file, and doing a windows update. Nada.

Running Quicken home and business subscription on Windows 10.