Library manager incomprehensible

Hello, the Halion tab has disappeared from my library manager, and I cannot have it back.
Thus, I cannot move the libraries:
I flag “move”, but then nothing happens, and don’t know how to go ahead

Can anybody help?

This seems an impossible event. Make sure your Halion instrument is installed and then download the Library again.

I re-installed the whole Cubase (what a disaster install), and now I can see the Halion libraries, but when I want to move them on an external HD, a pop-up menu tells me that the task has failed.

What seems impossible is in Cubase 11