I traded up to the SE and no longer have the Designer 1, but do have problems from time to time. Try a good cleaning as mops stated. My machine will tell me to check upper thread at times and it is my bobbin. Sometimes the bobbin threads are not wound tightly and it causes issues. Hope you can get it going for you.
I have a designer 1 but I have not yet got this problem.Thank you to mops for those advices which would be precious if this problem arrive.*4U
I have a designer 1. I have had the problem after using gold metallic thread, just a little bit snared somewhere and the problems started. Cleaning was the answer. The tie off / thread cutting hook may be clogged up with lint. Remove the bobbin case, remove the stitch plate (with the back of your cleaning brush), take out the black bobbin case holder and clean the whole lot thoroughly. That should do the trick. If not, consult your dealer. But I hope that won't be necessary.
Does your Bobbin Empty thing work? Soon as I have the tiniest bit of lint round the bobbin, the blooming detector does not work and the machine goes on stitching for quite a while and then it tells me the upper thread is broken - which it isn't - but I start changing it before I realise it's the bobbin that's run out.
the same thing arrive to me with saying that the upper thread was broken but it was teh bobbin which had the problem
sorry I don't have this kind of machine but here is a flower for you while you wait for your answer