The quicken one step update not working might cause a lot of issues. To fix this:

• Check for the latest Mondo Patch Update, and download it. Also, ensure that you have the latest version of Quicken;
• Restart Windows and then check if the problem persists;
• Restore the latest backup of Quicken files. This will reset the data to the one before the error;
• You can also try to Validate or Super Validate your Quicken data file.