Hi Chris,
Lets start afresh.
Please disable any Antivirus and firewall.
Please use Windows to uninstall FMS Data Manager. Specifically use FAQ - Charts desktop installer fails immediately
If they exist, please delete folders:
c:\ProgramData\Navigraph\FMSClient and c:\Program Files (x86)\Navigraph\FMS Data Manager.
Please download and install latest FMS Data Manager .
If still an issue, please post screenshots of Settings tab showing X-Plane path and Addon Mappings tab showing paths
Please let us know how you get on.
Cheers
Ian