Cannot accept access requests for webpages

Quick trouble-shooting question - I am trying to share an Express webpage with another user. If I send them the link to ask for access, they can click on it, but I cannot approve them. Basically, the approval screen pops up, but nothing happens when I click on the 'Accept' option (screen just loops). I can still add individuals though the invite option, but it's for a class of 150 students, so the process of emailing it out to all of them, and then getting them to duplicate the file would be very time-consuming.

This hasn't been an issue before, so I am wondering if it's just a bug in the system at the moment?

Thanks