snmp-agent target-host trap address udp-domain ip-address [ udp-port port-number | source interface-type interface-number ]

snmp-agent target-host inform address udp-domain ip-address [ udp-port port-number | source interface-type interface-number | [ vpn-instance vpn-instance-name ]

snmp-agent target-host trap ipv6 address udp-domain ipv6-address [ udp-port port-number | vpn-instance vpn-instance-name ] * params securityname security-name [ v3 [ authentication | privacy ] | private-netmanager | notify-filter-profile profile-name | ext-vb ] *

Even though checking the diagnostic information and discover this messages:

the version of SNMP can be V3 so the version mismatch might not be real. 

Best practice will be to check this too, if this messages are discovered.

This issue is caused by the Privacy/Encryption algorithm on Solarwinds that is AES256.

To eliminate the problem change the Privacy/Encryption in Solarwinds from AES256 to AES128.