This attribute has to do with the free radius attribute hint on compression type, this can be ignored and subscriber should be able login despite of this message as it is just a hint to use a compression protocol from free radius.
This Attribute indicates a compression protocol to be used for the link. It MAY be used in Access-Accept packets. It MAY be used in an Access-Request packet as a hint to the server that the NAS would prefer to use that compression, but the server is not required to honor the hint.
More than one compression protocol Attribute MAY be sent. It is the responsibility of the NAS to apply the proper compression protocol to appropriate link traffic