Seahub cannot create share link

Hi,

Currently I have a seafile server (community, psql / nginx) at version 6.3.
Since some updates ago I cannot create a share link from seahub - the popup is empty.

The only thing I can do from the “share” popup menu, is “create an upload link”.

Attached is a screenshot from the dev console.

Any help is appreciated!

P.S.: it is not the same issue as Can't create download link.
I already have the column seahub-db/share_fileshare/permission.