I was seeing the same issue, and removing the file from /var/ossec/ queue/agent-info worked like a champ for me.
A bug fix for v2.3.1?
- [ossec-list] Ossec Webui Displaying Removed Agents Bernard Golden
- RE: [ossec-list] Ossec Webui Displaying Removed Agen... Carter, Dennis A
- Re: [ossec-list] Ossec Webui Displaying Removed ... Bernard Golden
- RE: [ossec-list] Ossec Webui Displaying Remo... Chris Kolb
- RE: [ossec-list] Ossec Webui Displaying Remo... Carter, Dennis A
- Re: [ossec-list] Ossec Webui Displaying ... Bernard Golden
- [ossec-list] Re: Ossec Webui Displa... Dave S
- Re: [ossec-list] Re: Ossec Webu... Daniel Cid
- Re: [ossec-list] Re: Ossec ... Bernard Golden
- [ossec-list] Re: Ossec Webu... Dave S
