Misleading false failure message when trying to post a comment on an answer to your own post #1577
Description
When a user without the "Participate Everywhere" ability tries to add a comment to an answer to their own question (which they should be able to do), they receive an error page (not an HTML page, just a raw JSON error page) saying:
status: "failed"
message: "New users can only comment on their own posts and on answers to them."
Note that this screenshot is not the developer window, this is what is shown directly to the user.
In addition to causing confusion because the user should be able to comment, there is further confusion because the comment does save successfully, but the user is unaware of this due to the misleading error page.
This has since also been raised independently by a different user on Software Development Codidact's Meta: I comment on an answer on my question, and get this error: "New users can only comment on their own posts and on answers to them"