: The portal or gateway certificate has reached its end date.
: Network security software or a proxy might be intercepting the connection and presenting its own untrusted certificate. Palo Alto Networks Troubleshooting Steps GlobalProtect VPN Troubleshooting Guide globalprotect vpn failed to verify certificate
: An interactive troubleshooting button in the GlobalProtect client's Settings > Troubleshooting tab that scans the local certificate store. : The portal or gateway certificate has reached its end date