Print does not start over USB-stick Zaxe Z3/X3

There can be two reasons for this:
1) The file name is too long and / or uses special characters.
2) The USB stick is not compatible (X3 only).

Solution:
1) Rename the G-code. We recommend a maximum of 12 characters (numbers and letters)
2) Use USB stick from Zaxe (included in delivery). If this does not work, format the USB stick completely (FAT32).