I have a Janome 9000. I was winding a bobbin and

Various ideas in the link

https://www.google.com/search?q=Janome+500E++bobbin+winding+issues

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Slow down the speed of your machine while winding the bobbin. Winding slowly will prevent the thread jumping out of the guides but will also limit the amount of stretch applied to the thread as it is wound on the bobbin. You will also get a much more uniformly wound bobbin.

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did you click the bobbin holder over to the right? This should disengage the needle

Did you remember to slide the bobbin winder pin all the way to the left?

Double check you are threading correctly for bobbin winding. It should wind neatly till it can't turn, and then you stop winding; at least this is how it works on the 8000. Perhaps there is some thread blocking the thread guide for the bobbin winding

Take it to a Janome dealer for repair.

If the feed dogs are engaged/raised, have you sewn since winding a bobbin?

The machine may still be in "bobbin winding" mode.

Memory Craft has a bobbin winder on top of the machine.  It works beautifully, but wind it on slowly for better sewing function.

Under the top cover, on the right hand side where the bobbin winder is, there is a small switch which is activated when the bobbin is being wound. You will need to remove the cover and reposition the switch (it's located towards the front of the machine) to make it work properly.
sewman7

I have a Janome 9000, was sewing and broke needle, replaced and broke another. I didn't have machine threaded, took out bobbin and would sew a little and stop saying thread broke. I took off top plate and started machine again, sew a little and stop saying thread broke. So I took out bobbin case and sewed again and stopped repeating the message. Everything looks OK, bobbin case and top plate. I guess I want to know if the timing could be off or do you think it is the computer part of the machine...Should I take it to the Sewing Machine Shop??