Why do I have error messages with OpenVPN 2.6 firmware version 2.8H or higher (COMfortel 1400 IP/2600 IP/3600 IP) and firmware version 2.4B or higher of the D-Series?

With the update to OpenVPN 2.6, the obsolete `cipher` option has been removed.
If your OpenVPN client configuration no longer works, try replacing the `cipher` parameter with `data-ciphers` in your file.

Try the following change in the configuration file:

Replace the line:

cipher AES-256-CBC

with the following three lines:

#cipher AES-256-CBC
data-ciphers AES-256-CBC:AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305
data-ciphers-fallback AES-256-CBC

Restart the VPN on the phone.

If the VPN still does not work, further measures may be necessary on the client and/or server side.
In this case, talk to your system administrator.

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