My VP reported an error message that he received while trying to add @mention to the Comments of a SharePoint Online News post. After adding 12 @mention names he received the following error messages: "Could not complete that action" and "Couldn't post comment. Try again." Has anyone seen these error message when attempting to post Comments? Is there a limit to the number of @mention names you can enter in a Comment? A screenshot of the error message is attached. Thank you in advance for any assistance.