Unable to create gcode file usiing Print 5.0

Have new Ender 3v3 that prints well from supplied flash drive’s files.

When I use Creality print 5.1 I save the gcode (press print plate options). File saves to flash drive but printer will not read this file with flash drive installed.

Have used Ender 3 and Cura prior to new printer and new software.

Any suggestions.

Bob