You are right, we did not know (pinned by mistake).
I assumed that it would go away automatically. Why it should not?

Edit: to be clear, the alert is gone now. Thanks

Context
We are two players playing in multiplayer using the in-game "Host" option (no headless server). I am the host (mlomb).

Problem
There is a rogue "missing materials" alert that only appears to my friend (not the host). It should not be there, since there is nothing there. It does not ...