How to create discussion if the thread has been deleted?

[cthart]

I wanted to report the last score on the main tab of https://imslp.org/wiki/Suite_in_E_minor ... Sebastian)
The score itself indicates it's an arrangement for harpsichord, so it should be listed on the Arrangements tab.

But when I go to submit a discussion on this score it says
[Thread closed] Thread not found
Thread does not exist or was already deleted - go back to Overview.

This effectively prevents someone from starting a new discussion.

Is this intentional?