Hi @Zynthianers!
Update your software! There are some new improvements and fixes:
- Webconf tool => Drag&Drop multi-file upload for soundfonts and presets (thanks @mheidt!!)
- FluidSynth => Fix crashes after trying to load invalid/corrupted SF2 files
- Bugfix: Sync disk cache after writing files (config, snapshots, etc). Now you can safely unplug your Zynthian and the last changes wont be lost
- Install jack-smf-utils package, a MID-file player/recorder. Needed for upcoming features
For a complete list, check the repository commit list 
Enjoy!