There is no "Public link" button in the ticket and client cannot open it because of returning an error
The current troubleshooting guide will teach you how to solve the Public ticket error problem.
There are two indications of the problem. The one is that the Public ticket button itself is not appearing in the ticket. When everything is correct, it should be placed on the top right corner:
Note: For more information about the Public ticket feature, please check this article.
The indication that could guarantee that the problem is existing is that when the public link is opened, it returns an error instead of the public ticket view. The error warning message says that the page doesn't exist or has been deleted. For example, this situation could appear if the autoanswer contains public ticket macro. And, as a result, the client cannot open this link because it returns an error message to him:
The solution to both problems is to disable the Private option for the ticket itself. It is located in the top right corner of the edit issue mode.
And then both problems will disappear.
Note: Please keep in mind that if the problem is only related to the Helpdesk macro of the public ticket returning an error when clicked, then it is possible that the Public ticket feature is disabled, so please make sure it is enabled as described in this article.