fpl files locked in Garmin G1000

[Sitka21]

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?

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.  The same problem for all 13 routes that I recently produced but not for any produced a few weeks ago/last year.

Thanks