If you don’t mind, could you please provide a screenshot of the error message you described receiving? If needed, please refer to this Community FAQ for instructions on how to attach a screenshot. Alternatively, you can also drag and drop screenshots to your response if you are not given the option to add attachments.
I look forward to your response.
To make sure that Quicken is allowed to update and save its configuration files please check if Windows Defender Controlled Folder Access feature Ransomware protection is enabled. If so, configure it to add Quicken as an "allowed app" without turning off Ransomware protection. Perform the last step in https://community.quicken.com/discussion/7857675/faq-windows-defender-controlled-folder-access