Bad Password errors are typically due to password changes or expiration. When your password is changed for any reason, you will need to manually update your password within the Desktop Sync Settings page.
For Mac: To access the Settings page, click on the Desktop Sync icon from the tray and select Settings from the options.
For Windows: To access the Desktop Sync home page, double click on the Desktop Sync icon from the icon tray.
Once you access the settings page, hover over Settings at the top of the page and choose Account Settings from the drop-down menu. From here, you can update your password to match what you use in the Web UI.