Hi…,
Does this occur when accessing via a browser https://charts.navigraph.com ?
I suggest you start from scratch with latest Charts and Simlink . Please disable any Antivirus and Firewall.
Please completely uninstall Charts and Simlink using Windows Programs and Features exactly as under .
If they exist delete directories
c:\Users\username\AppData\Roaming\Navigraph and c:\Program Files\Navigraph
Then download and install latest Simlink and Charts Desktop using the default prompted locations. Do not overrule.
Restart computer.
Cheers
Ian