Last Inventory Collection Status - ERROR-CONNECTION

Added a single 4500 to inventory and able to see the interfaces and their status, but in the Device Inventory showing ERROR-CONNECTION for collection status. It says:

 "The device connection could not be established. The device may be too busy or device reachability or line configuration may be having issues. APIC-EM will attempt to resync the device in sometime."

Start by verifying that there is connectivity.  Try ssh from grapevine to the device. Is it possible to do a snmpwalk.  Is cpu on the 4500 within acceptable ranges.

 Jul 11 10:31:33: %SSH-3-DH_RANGE_FAIL: Client DH key range mismatch with maximum configured DH key on server

Jul 11 10:31:33: %SSH-5-SSH2_SESSION: SSH2 Session request from 172.16.69.77 (tty = 1) using crypto cipher '', hmac '' Failed

Jul 11 10:31:33: %SSH-5-SSH2_CLOSE: SSH2 Session from 172.16.69.77 (tty = 1) for user '' using crypto cipher '', hmac '' closed

Able to ssh now from grapevine. Need to add

 KexAlgorithms=curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1

 to the /etc/ssh/ssh_config file.