Crucible Logical Flaw "You cannot forge a crucible passive tree onto a unique item here"

But well. When I see the tree does not fit the weapon/build, what's next? restart?

There is a primeval remnant that allows you to transfer crucible tree from a non-unique to unique. Its much rarer, I haven't seen one yet but I've seen people on stream doing it.

I think they come from the much rarer crystalline geodes, but not sure.

It's very early in league, people are still discovering the mechanics