To start: I've built several mods for playtesting, and have successfully shared them with multiple different groups over several years. I haven't shared anything in a while, though, and it no longer works.

Specifically, making the visibility of a mod "Unlisted" and then sending out the sharing link gets the other people a "hidden or do not have permission to view it" error. I am now getting the same problem when another person has added me as a collaborator on a mod.

When I try to look at my workshop mods, I get a notification that someone has attempted to add me as a collaborator, and I'm asked to review and confirm, but the link gets me the permission error.

Approval request[www.dropbox.com]

Permission error[www.dropbox.com]

I have double-checked with the creator that the mod is marked as Unlisted.