If I had to take a guess from the names, DeadlyDan_MapFog or Kylock Time System might be doing it. What appears to be happening is that a plane object is being saved to a save file, which is bad. Figure out which script is causing the problem by taking them out one by one until the error no longer occurs. Like I said, it is likely one of the two I mentioned and likely Kylock's as I've heard a fair number of complaints about his scripts.
Once you figure that out, post a link to the script and I might be able to take a look or refer you to another script with the same function.