snmpwalk: Unknown user name (SNMP v3)

I'm trying to run SNMP version 3 but I'm getting this error:

snmpwalk: Unknown user name (SNMP v3)

This is the command I'm using

sudo snmpwalk -v3 -u bob -l AuthPriv -a SHA -A bobpassword -x AES -X bobpassword 127.0.0.1

I've created the user bob with this command:

net-snmp-create-v3-user

I created the user bob with the password bobpassword. For some reason it tells me that the user is unknown. Any ideas? Thanks