There are a number of reasons a link might not work.
It could be:
- The link is expired. Each link expires at the end of the 30-day period during which it was issued.
- It was opened on a desktop. The link will only work on a mobile device.
- All the invites are used up for the month. A link can be sent as many times as you like but it’s only valid for the first 5 people who use it.
- This person has opened their own link (hey, it happens).