fpl files locked in Garmin G1000

[routeconverter]

Hoping someone may be able to help with this issue.  I recently converted a route made up of many user waypoints from gpx to fpl files in routeconverter for use in an aircraft using a Garmin G1000.  I have used this method successfully in the past.  This time, when trying to import the fpl files into the G1000 I am receiving an error that files are locked.  Any ideas what the issue could be?

What exactly does "that files are locked" mean? Could you send me the error message?

I always have to rename the waypoints when converting to make them shorter and get rid of any extra characters.  A naming problem is the only thing I can think of but it seemed to work fine in routeconverter. 

Could you provide me with files that worked and files that fail?

What exactly do you do, when shorting the waypoint names? I could try to do this in the software instead of manual work.