[Bhruic]

In the ses.kfs file (it's just a zip file, you can open it with something like 7zip), you'll find the magic_temper_diff.atom file. Cut out the following (lines 202-210):

  1 {
    sound {
      animation=default
      frame=0.01/2.00999999
      restart=true
      file=magic_temper_diff
      fadetime=60
    }
  }

Or, if you wish, you could look up another soundfile to replace for the non-existent one, but that's probably more work.