A user may not see the Sign Up button beside an event if:
- You have chosen NO as the Allow Users to Self-Register setting. (You can fix this on the Edit page for the event.)
- The cutoff date defined in the Self-Registration Cutoff field has been met for the event.
- All slots for the event are taken and the event is full.
- All slots for the event are reserved for a group to which the user does not belong.
- The Overflow option is not enabled for the Unaffiliated Users group (you can fix this on the event by editing the User Group Reservation).