Hi, This is my requirement
In the newsletter mails, we need to give users the option to opt-out of the newsletter mails while not being blacklisted. Create a web app to do this and create a personalization block to add the URL to the newsletter delivery
I have created a web application , a Delivery template, and a personalization block for this and running a campaign in which I have inserted a web application unsubscription link. Subscribed recipient is getting mail after running a campaign

and after clicking on the unsubscription link it redirects to

and after checking the checkbox and clicking the unsubscribe button I am getting this error

Can anybody help me with this, also please let me know how to check if the recipient has been unsubscribed. Immediate help will be highly appreciated