MWG is unable to download the CRL from that host. Actually www.ips.es is dead since a long time and we have removed the CA as it has been disabled by the browser vendors as well. When you still see this error message this could have two reasons:
1.) You are not using the McAfee Maintained RootCA list, e.g. the list of RootCAs that automatically updates, but have a static list in place. In that case you need to manually remove this CA:
Subject Common Name (CN) IPS CA Chained CAs Certification Authority Organization (O) email@example.com C.I.F. B-60929452 Organizational Unit (OU) IPS CA Chained CAs Certification Authority
2.) If you have the Maintained RootCA list the CA is already removed, but MWG needs to be restarted.
Thanks Andre, the error message is gone.