Make sure the peer ID information for the local certificate selected in VPN > Settings > GroupVPN matches the certificate imported into GVC:
Peer ID types and their information must be entered exactly as found in the data section of the local certificate imported into GVC or the client won't be able to establish a tunnel. Keep the following in mind when entering peer ID information:
Make sure the certificate imported into GVC matches one selected on the Gateway Certificates menu found at VPN > Settings > GroupVPN > Edit. These certificates must match and may not be swapped among different installed copies of GVC.