Non SSL on an SSL virtual - how to interpret log?

We are seeing

Jul  5 14:24:07 ext-lb02 warning tmm1[24783]: 01260009:4: Connection error: ssl_passthru:4062: not SSL (40)

What does the "4062" and the "(40)" mean? We are trying to track down that is causing this log entry to appear. (Seen in TMOS 12.X and 13.X)