Every time I try to Navigate in DMD2 I get Calculation Error There was an error calculating the route! Please try again, if you are off road try the mixed profile! java.long.RuntimeException: error reading datafile W5_N50.rd5: java.io.IOException: top index checksum error This is both for holding down a point on the map to navigate to or importing gpx files.
That means the calculation file download is not good, probably the download was not completed.
Delete whatever map file it is for the country in question and download again.
Let me know if it continues to happen.