Avamar client activation error "Signing CSR failed"

2017-02-15 13:05:35 avagent Info <5705>: Updating IP address with the MCS. local IP='<CLIENT-IP>', registered IP='(none)', port changed:false
2017-02-15 13:05:35 avagent Info <18918>: Registration: Processing secure registration with the MCS.
2017-02-15 13:05:35 avagent Info <18921>: Registration: Requesting root CA from the MCS.
2017-02-15 13:05:36 avagent Info <18926>: Registration: Saving root CA.
2017-02-15 13:05:36 avagent Info <18928>: Registration: Creating certificate signing request.
2017-02-15 13:05:42 avagent Info <18930>: Registration: Sending the certificate signing request to the MCS.
2017-02-15 13:05:43 avagent Error <5320>: Received from MCS#100200:Signing CSR failed.
2017-02-15 13:05:43 avagent Error <18931>: Registration: Unable to send the certificate signing request to the MC.
2017-02-15 13:05:43 avagent Info <18936>: Unable to securely register with the MCS (<AVAMAR-SERVER-IP>)
2017-02-15 13:05:43 avagent Error <6053>: Error trying to update MCS with new ip address
2017-02-15 13:05:43 avagent Info <6626>: Agent Main: Client ID (cid) = xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
2017-02-15 13:05:43 avagent Info <18918>: Registration: Processing secure registration with the MCS.
2017-02-15 13:05:43 avagent Info <18921>: Registration: Requesting root CA from the MCS.
2017-02-15 13:05:43 avagent Info <18926>: Registration: Saving root CA.
2017-02-15 13:05:43 avagent Info <18928>: Registration: Creating certificate signing request.
2017-02-15 13:05:44 avagent Info <18930>: Registration: Sending the certificate signing request to the MCS.
2017-02-15 13:05:45 avagent Error <5320>: Received from MCS#100200:Signing CSR failed.
2017-02-15 13:05:45 avagent Error <18931>: Registration: Unable to send the certificate signing request to the MC.
2017-02-15 13:05:45 avagent Info <18936>: Unable to securely register with the MCS (<AVAMAR-SERVER-IP>)
2017-02-15 13:05:45 avagent Info <5321>: Unable to connect to Management Console (<AVAMAR-SERVER-IP>), sleep 43 minutes, 9 seconds before retry

02/15-12:59:38.00044 com.avamar.mc.cr.messages.CertificateSigningRequestHandler.handle
WARNING: Cannot get SAN, fail CSR signing...
02/15-12:59:38.00044 com.avamar.mc.cr.bcConnection._sendReply
FINE: MC->Cl <CLIENT-IP>:52795 <message  errno="100200" errdesc="Signing CSR failed." ack="no" type="response" sync="fg"  />
02/15-12:59:38.00229 com.avamar.mc.cr.bcConnection.readClientMessage
FINE: Cl->MC <CLIENT-IP>:52796<client isclientos="1" ack="yes" type="root-cert" ipaddr="<CLIENT-IP>" msgver="1" hostname="CLIENT-HOSTNAME" os_type="Windows 7 Enterpris
e Edition Service Pack 1 64-bit" mcsaddr="<AVAMAR-SERVER-IP>" bestalg="rsa" cid="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" version="7.3.100-233" />
02/15-12:59:38.00230 com.avamar.mc.cr.bcConnection.validatePageAddress