When you try to edit a phone after you upgrade to CUCM 12 you get an error of
"Update failed. SSH Password is not valid. SSH Password is an encrypted value containing up to 288 hexadecimal characters (0-9 and A-F)"
You have to run the following command on CLI in irder to clear any password set
run sql update device set sshpassword = '' where name = "SEP1234AAAABBBB"