Workaround for issue saving sessions/layers in JMARS 5.6.5 release.

If you are having trouble saving a session or a layer file in version 5.6.5, the workaround is to open up the focus panel of the Shape Layer and select Feature->Edit Columns. Next, select any calculated fields of types: Center Longitude, Center Latitude, Perimeter or Enclosed Area. For each of those, select the appropriate option (units, longitude system, latitude system), check the "Update All Rows" checkbox, and click "Update Features". This will allow you to save your session or layer file. There is a fix available (5.6.5.1) that prevents this from happening.