Confirmed.
I attempted to make Glowing Concoction at every skill-up from 90-100.
"You are too inexperienced in your craft to even consider attempting this combination."
You cannot make it until 100 & I succeeded at 100 first go.
Message was;
"You can no longer advance your skill from making this item.
You have fashioned the items together to create something new: Glowing Concoction"