[snmp] Net::Netmask not present: no scan possible

Server and agent are on Centos 7 servers. OCS 2.2.1, OCS-NG_unified_unix_agent_v2.1.1

I've been trying to add all kind of notations for snmp_network in the tab network scans for the machine where the agent is running but I keep only getting Netmask not present: no scan possible in the log.

Can anybody help me.