Connection fails with "Fatal: Unable to negotiate a key exchange method" message

The problem may be related to the potentially incompatible changes introduced in OpenSSH 6.7 (included in Copssh 5 and higher) to remove unsafe algorithms.

If you run Copssh 5.8.1 or higher, you can update the configuration via GUI:

Copssh Control Panel - Configuration - Advanced - KexAlgorithms

  • Alternatively, you can add following line to the section of the configuration file control/bin/copsshcp.config before starting Copssh Control Panel:

KexAlgorithms=+diffie-hellman-group1-sha1

  • Restart the service via Copssh Control Panel