How can I fix a "Cannot add static actor to dynamic actor" error?

I have a static mesh (weapon) and a dynamic mesh (third person character) they both have sockets but when I try to attach the weapon I get the above error. I’ve tried searching for the exact error and have found nothing. What can I do to fix this?

In case anyone needs this I just created an actor blueprint and attached it that way

In case if someone still have the same issue…

You need to switch Mobility property to Movable in tranform category.

thk i was serching for whole day finally got

Ma man