Same number for the next invoice

Hi, I issued the invoice number 160 client 1 received it, but did not paid just yet.
Then I issued the invoice for the client 2, and the number is still 160
Then client 3 gets invoice number 161.

What should I do with client 1. I can see email tracking with postmarkapp, can click on the email it was sent to client 1, but it gives error 500

[2022-08-23 11:45:03] production.ERROR: Attempt to read property "invoice" on null {"exception":"[object] (ErrorException(code: 0): Attempt to read property \"invoice\" on null at /var/www/public_html/app/Http/Controllers/ClientPortal/InvitationController.php:89)

current Invoice Ninja v5.5.5


@david any thoughts?


Did you click on the link via the preview panel?