Please make sure you have the most recent version of RDB Mobile and update if necessary from the app store.
If you have the most recent version, try uninstalling and reinstalling the app, make sure you have the setup details before doing this.
⚠️ Important: Use SSL must be turned on; under the general Settings screen of the mobile device and then the RDB Mobile heading.
You must be using the Use Windows Security option in your RDB user account.