Could you please elaborate a bit more on the error message you have received? Perhaps, the issue was caused by the Viewer configuration file being somehow corrupted by some antivirus or firewall software.
Please, try the following: 1. Fully exit the Viewer File -> Exit. 2. Locate the file config_4.xml in the C:\Users\[Your_username]\AppData\Roaming\Remote Utilities Files\ folder. Please note that the AppData folder might be hidden by default in which case you need to enable Hidden files and folders in Windows Explorer settings. 3. Remove the config_4.xml file fr om that folder. This will reset the Viewer settings. Your address books won't be affected by this action. However, in case if your address book connection records were also affected by the issue, please try checking this location wh ere the address book backup files are stored: C:\Users\user_name\AppData\Roaming\Remote Utilities Files\backups\ Please note that the automatic address book daily backup is enabled by default and includes the general (default) address book as well as any custom address book that was loaded in the Viewer. 4. Run the Viewer. Please note that you will need to register the Viewer with your license key again. If the license key was lost, you can restore it using this Lost Key recovering form.