SNMP error on Localhost

hi, i have a problem with localhost about snmp as this:

i checked the validate.php and everything in ok.
can anyone help what should i check and what is the solution?

check and see if snmp is running on localhost.

i do “service snmpd restart” and “systemctl enable snmpd.service” and snmpwalk command and it seems it should be ok.

ok check to make sure you have community string set in snmpd.conf

i edited like this:

What is returned by systemctl status snmpd?

thanks, i solved it. it was because of snmp update.