Hello everybody,
not sure this issue has already been seen / experienced / reported by somebody else here (in earlier versions), so i will try ot explain the situation as good as possible.
Put my computer to hybernate yesterday evening with Luban running and connected - did finish a print job and showed 99% of progress. J1 was switched off over night.
Restarting everything (PC + J1) this moring showed Luban still connected to the printer ( - okay, maybe there’s a auto-reconnect? - ) Sliced a file, exported to workspace and hit “Send to Device” - file transfer box displayed… but no progress… (- okay no auto-reconnect… - ) Closed everything after ~2min and hit “disconnect” without any success - Luban stuck…
Okay - restarted Luban, sliced the file, exported to workspace, connected to J1 (did work now) and sent the file - seems to be working… file transferred.
So far so good 
Then: Start the print in Luban to get my file printed… heading to the coffee machine and returned approx. 10min later.
J1 stuck in preheating 
- no progress on print
- no movement
- no further activity!
Okay - Cancelled the print, select transferred file from local storage and hit “print” again…
Similar issue:
- no preheating
- no progress
- no movement
- literaly nothing…
Just stuck at 0% and that’s it…
Fix by now: restart J1…