ERROR: none message must be encrypted

[fuzion1]

We have an IPSec setup with one of our locations.  It is spamming this message in the firewall IPSec logs twice a second. This is the only message it is showing. Does anyone know what this is or how i can fix it?  I think its causing the IPSec connection to break every once in a while.  It broke twice last week.  I could not find any good information on this forum about this topic.

Thanks in advance for the help.

May 13 13:44:04 racoon: [Nashville]: [x.x.x.x] ERROR: none message must be encrypted
May 13 13:44:05 racoon: [Nashville]: [x.x.x.x] ERROR: none message must be encrypted
May 13 13:44:09 racoon: [Nashville]: [x.x.x.x] ERROR: none message must be encrypted
May 13 13:44:09 racoon: [Nashville]: [x.x.x.x] ERROR: none message must be encrypted