Inviting users to Discourse?

[IAmGav (Gavin Perch)]

Sounds like the invite link expired or the invite link has been revoked.

Edit: Here is something that will help you explain invites

Configure how users can create and send invites for others to join your community

Discourse allows users in permitted groups to invite new users into the community (default trust level 2). Invites can be configured to redirect the new user to a specific topic when they first join the site. Invites can also be configured to add the user to custom Discourse groups when they accept the invite. Related site settings The following site settings can be adjusted to configure how invites work on your site: Name Description invite allowed groups The groups that are allowe…