I am not aware of any norton program for Linux, and do not have such installed. Also, the game is not installed on Linux, but run straight out of a jar. I replaced the jar, no change. Principle effect of the error; my map, my terraformed map, is gone, and I now appear deep underground, not in a cavern, but suffocating in the midst of blocks, in some strange world. A much smaller world.
Also affects 1.8 on Linux 3.13.0-35-generic #62-Ubuntu; game does not run fine, but loses map data.
Rolled back to an older version, managed to load, no error, map still funny. Now using 1.8, no error, map wrong.