Hi Elizabeth,
Thank you for contacting us and I'm sorry about the issue you are experiencing. mSecure 5 will not sync with mSecure 4 or it's sync features. If you previously set up Dropbox syncing in mSecure 4, please download mSecure 4 from your purchase history and set up Dropbox syncing on that app. Once you have all your information synced to mSecure 4 on your device, you can create an email backup that can be used to restore your data in mSecure 5.
1. Download mSecure 4: https://support.msecure.com/en/support/solutions/articles/36000064658
2. Setup Dropbox syncing in mSecure 4: https://support.msecure.com/en/support/solutions/articles/36000028452
3. Transfer information from mSecure 4 to mSecure 5: https://support.msecure.com/en/support/solutions/articles/36000064653
Elizabeth