The Solved button is dimmed (grayed out) on my messaging ticket

Issue symptoms

When I open a messaging ticket, I cannot solve it. What is causing this behaviour?

Resolution steps

While the conversation is active, only the ticket assignee, who owns the conversation with the end user, has the ability to use the Solved status when updating the ticket.

If you are not the Assignee of the ticket, you cannot set an active messaging ticket status to Solved.

For a similar issue, see this article: Why can't I set my ticket to solved?