When signing up, I (or my guest) get redirected to a "Not Found" page
There's a known issue that happens only in rare cases, where the guest uses an email address that exists in one of your Project Broadcast contacts, but with a different phone number. PB rejects the contact being added and it causes an error, because PB does not permit you to have two different contacts with the same email address.
As a result, the PB error interrupts the addition of that guest to your Contacts, an the redirect to the Contact's Party Page link fails.
This most commonly happens when a Sparkhub user is testing their own setup, since they may already exist in their own PB account as a Contact with the same email but a different phone number.
What to do
Are you (or the guest) by chance signing up with an email that is on a different contact in your PB account?
If so, try signing up again but leave the email field blank.
We do plan to correct for this but in the meantime, rest assured that it won't happen commonly (since most of your party guests aren't going to have multiple phone numbers in your PB contacts).