I love to use different threads & recently worked out how I could get the holoshimmer thread to work on the 15000 (l had to bypass the top tension leaf). However today I was driven to absolute distraction by an ordinary type metallic thread that I have used many times in both my old 3500 & the 9700 with no trouble at all!
As soon as I took my eye off the embroidering when "sniggle snam it was in a jam" of epic proportions, I'm talking about having to get my blade type unpicker to slide in under the hoop & cut the tangled threads loose.
And then on top of those woes of course the needle threader wouldn't work on the purple tip needle (although I did change the needle to the top stitch 90/14 for the metallics which threads easy peasy). Oh boy, not what I would call a therapeutic experience, lol!
So it really made me question just why that same metallic thread that had worked fine on all my earlier machines just wouldn't work on the 15000 ... Disappointing to say the least ... ☹️