The only way I found to do that is to edit the midi file (using tools from Günter Nagler) and to manualy add a "key" command.
Do you know other way to do that ?
Inside NoteWorthy Composer ?
Thanks in advance.
Do it manually after the import is complete.
If a key signature is not present, add a C Major key signature to the staff, and proceed as follows.
Once a key signature is present, then use the change key signature procedure, as outlined in the latest User's Guide (Bersion 1.55, Page 21), help file (Common Question #6), or the forum thread at https://forum.noteworthycomposer.com/?topic=2.
See also: https://forum.noteworthycomposer.com/?topic=872,https://forum.noteworthycomposer.com/?topic=929, https://forum.noteworthycomposer.com/?topic=637