During this procedure, you will be completing the following general steps, as necessary.
- Manually add time servers.
- Disable Certificate Validation.
- Erase the local configuration and restore factory settings.
- Set the router DNS to 184.108.40.206 and 220.127.116.11, then power-cycle the network.
You have the option of completing Steps 1 through 3 above either
- On the phone itself (this does not require a computer, but can be more time-consuming).
- Via the phone's web interface (this is often more convenient, but requires a computer on the same network as the problematic phone).
Please note that after each step above, you will reboot the phone, at which point the DHCP server may assign it a different IP address. If you elect to complete the steps via the phone's web interface (GUI), you will need to re-check the IP address on the phone itself before beginning each subsequent step (if necessary).
If you find the error clears at any point along the way, you may conclude your troubleshooting.