What to do for the Quicken Will Not Open issue?
You may face the Quicken Will Not Open error after a recent product update. It's possible that Quicken won't launch because of a problem with the installation. Computer restarting will quickly fix this problem.
Important: Quicken is not intended for use with shared or network drives (such as OneDrive or Google Drive). While it is possible to backup data files to a network, Quicken shouldn't be opened or used from a network. Make sure Quicken is set up on the hard disk of your computer.
https://www.quickensupporthelpnumber.com/blog/fix-quicken-wont-open-after-installing-windows-latest-update/