Hi all,
I have same problem but can't upgrade system with scripts pve5to6
FAIL: Unsupported SSH Cipher configured for root in /root/.ssh/config: 3des
my file /root/.ssh/config
Ciphers blowfish-cbc,aes128-ctr,aes192-ctr,aes256-ctr,arcfour256,arcfour128,aes128-cbc,3des-cbc