Can't sell weapons...Why?

[stilbe]

It says I have to sell weapons because it's above the limit (21). However, some weapons, in this case all that I have left, cannot be sold. I'm stuck now, it says I have to get rid of them but it doesn't allow me to. Why is that? Is that a bug?

[null]

Guess: Because you're dismantling them.

You can only dismantle weapons with elements.
You can sell any weapons. Selling icon is a bag.