Hi…,
Welcome.
Restart computer and try again.
Check you have installed the latest SimBrief EFP App V 1.3.2 in latest Hub v 1.2.24
You might try uninstall/reinstall.
Check you have a valid internet connection. Maybe try disconnecting Antivirus and firewall. Try connecting to internet via mobile hotspot.
If still a problem, please posts a screenshot showing the error using Guide to posting Screenshots.
Cheers
Ian