If it's a small cone spool, a Deelibob works. Large cones like serger types can use the same cone holders sergers use.
If you can't fit it upright, get a metal cone holder.
I've got some King Tut I have trouble with. They are vertical, but the thread seems to be crosswound at the bottom of the spool. Every time thread has broken, it's at the underside of the spool. Never at the top. If you pull it (unwind it) by hand, you can feel it catch at the bottom, so it isn't the machine. The emptier the spool gets, the worse the hangup.
I've learned to unwind cones by hand. I've had serger cones that have either a cut thread or tangle for a couple of revolutions in the same spot. Saves trouble unwinding by hand. You can find the glitch without having to rethread the machine constantly.