Non english charcters in midifile name

Hi guys. I dont know if its a general MIDI issue or what. But if i make a midifile for controlling dmx and use swedish letters like å,ä, ö in it. It wont playback midi from utrack24. I see the MIDI icon in display and its only the files with swedish letters that dont transmit MIDI. I i change name it works fine. Utool replace the letter with _ (undeline) when exporting to USB stick