Hi.
EasyMorph v5.6 and higher should support the following host key algorithms:
ssh-ed25519
ecdsa-sha2-nistp256
ecdsa-sha2-nistp384
ecdsa-sha2-nistp521
ssh-rsa
ssh-dss
rsa-sha2-256
rsa-sha2-512
and the following key exchange methods:
curve25519-sha256
curve25519-sha256@libssh.org
ecdh-sha2-nistp256
ecdh-sha2-nistp384
ecdh-sha2-nistp521
diffie-hellman-group-exchange-sha256
diffie-hellman-group-exchange-sha1
diffie-hellman-group16-sha512
diffie-hellman-group14-sha256
diffie-hellman-group14-sha1
diffie-hellman-group1-sha1
with the following encryption methods:
aes256-ctr
3des-cbc
aes128-cbc
aes192-cbc
aes256-cbc
blowfish-cbc
twofish-cbc
twofish192-cbc
twofish128-cbc
twofish256-cbc
arcfour
arcfour128
arcfour256
cast128-cbc
aes128-ctr
aes192-ctr
and MAC algorithms:
hmac-md5
hmac-md5-96
hmac-sha1
hmac-sha1-96
hmac-sha2-256
hmac-sha2-256-96
hmac-sha2-512
hmac-sha2-512-96
hmac-ripemd160
hmac-ripemd160@openssh.com
Please check the vendor sftp server for supported algorithms.
Also, what public/private key are you using (e.g., RSA, DSA etc)?
Ensure you're trying to connect to the same server using the same computer and private key/account name.