FortiClient Business on iOS Can Register with Fortisase, but not connect to VPN / SPA

[kingharrison]

I am trying to setup my iPad and Phone on Fortisase and then connect to the VPN. 

Registering them on Fortisase has worked and I added the SSL cert. 

But when I try to connect to the VPN, type in the user and pass (which are correct because that is how I connect on my laptop) it fails. It says Internal Error. I am using the app 7.4.3.0.161 thats available in the App Store. 

All help appreciated. 

[Dhruvin_patel]

Greetings!

To troubleshoot the issue with connecting FortiClient on iOS to FortiSASE VPN, follow these steps:

1. Check the VPN settings on the FortiSASE portal to verify that they match the settings used on your laptop for successful connection.
2. Confirm that the FortiClient app on iOS is updated to the latest version (7.4.3.0.161).
3. Double-check the username and password entered on the FortiClient app to ensure they are correct.
4. If the issue persists, try restarting the FortiClient app and the iOS device to see if it resolves the internal error.
5. If the problem continues, review the FortiClient logs for more detailed error information to pinpoint the cause of the internal error.

By following these steps, you should be able to troubleshoot and resolve the issue with connecting FortiClient on iOS to the FortiSASE VPN.

https://community.fortinet.com/t5/FortiGate/Technical-Tip-SSL-VPN-user-cannot-be-authenticated-and-c...

https://docs.fortinet.com/document/fortisase/latest/sia-agent-based-deployment-guide/787383/connecti...

https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-iPhone-users-unable-to-connect-to/ta...

https://community.fortinet.com/t5/FortiSASE/Troubleshooting-Tip-FortiSASE-SSL-VPN-is-reaching-at-40-...

https://community.fortinet.com/t5/FortiGate/Troubleshooting-Tip-FortiClient-TLS-error-5029-failed-to...

Regards! 

[kingharrison]

Thank you for the guidance. I went through all and got to the last one. Looking at the logs, it appears this is the issue saying error: data error. I removed the VPN address. None of this seems to be improperly setup. 

2025-01-31 16:48:33.589: [SSLVPNTunnel:122 - startTunnel]: Authenticated
2025-01-31 16:48:33.591: [SSLVPNTunnel:129 - startTunnel]: Kick off the DTLS connection to the server...
2025-01-31 16:48:33.593: [SSLVPNTunnel:233 - networkConnectionStateDidChange]: Tunnel connection state changed to CONNECTING
2025-01-31 16:48:33.684: [SSLVPNTunnel:237 - networkConnectionStateDidChange]: Tunnel connection state changed to CONNECTED
2025-01-31 16:48:33.685: [DTLSNetworkConnection:100 - startHandshake]: start handshake
2025-01-31 16:48:33.686: [DTLSNetworkConnection:154 - sendHello]: send hello
2025-01-31 16:48:33.687: [DTLSNetworkConnection:160 - sendHello]: dtls ver: 2
2025-01-31 16:48:33.688: [DTLSNetworkConnection:168 - sendHello]: send clthello-2: total bytes: 402
2025-01-31 16:48:33.689: [DTLSNetworkConnection:223 - sendHelloInMultiplePackets]: sending clt-hello2 msg: index: 0, bytes: 402
2025-01-31 16:48:33.717: [DTLSNetworkConnection:154 - sendHello]: send hello
2025-01-31 16:48:33.718: [DTLSNetworkConnection:160 - sendHello]: dtls ver: 2
2025-01-31 16:48:33.719: [DTLSNetworkConnection:168 - sendHello]: send clthello-2: total bytes: 402
2025-01-31 16:48:33.720: [DTLSNetworkConnection:223 - sendHelloInMultiplePackets]: sending clt-hello2 msg: index: 0, bytes: 402
2025-01-31 16:48:33.721: [DTLSNetworkConnection:154 - sendHello]: send hello
2025-01-31 16:48:33.722: [DTLSNetworkConnection:160 - sendHello]: dtls ver: 2
2025-01-31 16:48:33.723: [DTLSNetworkConnection:168 - sendHello]: send clthello-2: total bytes: 402
2025-01-31 16:48:33.723: [DTLSNetworkConnection:223 - sendHelloInMultiplePackets]: sending clt-hello2 msg: index: 0, bytes: 402
2025-01-31 16:48:33.724: [DTLSNetworkConnection:154 - sendHello]: send hello
2025-01-31 16:48:33.725: [DTLSNetworkConnection:160 - sendHello]: dtls ver: 2
2025-01-31 16:48:33.725: [DTLSNetworkConnection:168 - sendHello]: send clthello-2: total bytes: 402
2025-01-31 16:48:33.726: [DTLSNetworkConnection:223 - sendHelloInMultiplePackets]: sending clt-hello2 msg: index: 0, bytes: 402
2025-01-31 16:48:33.727: [DTLSNetworkConnection:154 - sendHello]: send hello
2025-01-31 16:48:33.727: [DTLSNetworkConnection:160 - sendHello]: dtls ver: 2
2025-01-31 16:48:33.728: [DTLSNetworkConnection:168 - sendHello]: send clthello-2: total bytes: 402
2025-01-31 16:48:33.728: [DTLSNetworkConnection:223 - sendHelloInMultiplePackets]: sending clt-hello2 msg: index: 0, bytes: 402
2025-01-31 16:48:33.729: [DTLSNetworkConnection:154 - sendHello]: send hello
2025-01-31 16:48:33.729: [DTLSNetworkConnection:160 - sendHello]: dtls ver: 2
2025-01-31 16:48:33.730: [DTLSNetworkConnection:168 - sendHello]: send clthello-2: total bytes: 402
2025-01-31 16:48:33.730: [DTLSNetworkConnection:223 - sendHelloInMultiplePackets]: sending clt-hello2 msg: index: 0, bytes: 402
2025-01-31 16:48:33.731: [DTLSNetworkConnection:257 - connectionTunnelReadPacket]: error: data error
2025-01-31 16:48:33.731: [DTLSNetworkConnection:342 - connectionTunnelReadNextPacket]: error: unable to read next packet: Error Domain=com.fortinet.vpn Code=-3 "Internal error." UserInfo={NSLocalizedDescription=Internal error.}
2025-01-31 16:48:33.732: [SSLVPNTunnel:221 - networkConnectionDidClose]: closeTunnelWithError : Error Domain=com.fortinet.vpn Code=-3 "Internal error." UserInfo={NSLocalizedDescription=Internal error.}
2025-01-31 16:48:33.732: [DTLSNetworkConnection:95 - cancel]: connection cancel
2025-01-31 16:48:33.732: [SSLVPNAuth:70 - logout]: doLogout
2025-01-31 16:48:33.733: [SSLVPNAuthClient:114 - remoteGetLogout]: remoteGetLogout
el connection state changed to CANCELLED
2025-01-31 16:48:33.733: [PacketTunnelProvider:352 - tunnelDidClose]: Tunnel being closed
2025-01-31 16:48:33.733: [SSLVPNAuthSession:60 - startSessionTask]: https://my_fortisase_vpn:443/remote/logout
2025-01-31 16:48:33.734: [PacketTunnelProvider:356 - tunnelDidClose]: Closed while starting, canceled with error: Error Domain=com.fortinet.vpn Code=-3 "Internal error." UserInfo={NSLocalizedDescription=Internal error.}
2025-01-31 16:48:33.829: [SSLVPNAuthSession:116 - urlSession]: Server cert is trusted