I also had years with my 15000- my dealer was retiring a few yrs back and I had started getting this message but let her take care of her customers before we looked at mine!!!
Ended up after she tried many things shipping it to janome ! Came back & was fine until about 9 mths
Later Started giving me message again!!
Then Covid happened!!
I have been able so far to get error message rest!!
One time I noticed a small bit of thread caught in bobbin area! Removed it and it reset !!
Frustrating for sure!
I have to speak with another dealer to see if he has dealt with this issue!!
Really don’t want to ship as it should have been fixed 1st time !
Kaye in LA