The rule for creating a new file in the Sdui cloud is parallel to the rule for uploading a file and is thus tied to the one-way function of the chat.

The group admin can create a new file at any time.

All other members of the group can only create a new file when the chat is open, i.e. when the one-way function is disabled.
Although these users have the option of creating a new file and editing it, they cannot share it with the other group members for joint editing. This must be done via the group admin.