Help:DiscussionTools/Why can't I reply to this comment?

Discussion pages have no limits on the available formatting. While DiscussionTools is able to recognize comments in most cases, there are some situations where it's ambiguous or impossible to tell whether some fragment of the page is a comment, or where the reply to it should be added. Whenever the correct behavior isn't clear, the tool will not allow replying rather than guess and potentially further mess up the page.

This page documents some of the errors you might encounter, their causes and solutions.

(no "reply" link appears)
You'll see this when the signature for that comment could not be detected.

Unsigned comment
This may be obvious, but just for completeness – if there is a comment that has no signature, it won't be detected. Discussion pages may contains content other than comments (e.g. various header templates), which can't be reliably distinguished from unsigned comments, and adding reply links to it would be unexpected.

If someone else already replied to that comment manually, their reply and the original unsigned comment will be treated as a single multi-line comment, leading to weird behaviors.

No date and time
If a signature is missing the date and time, the comment also won't be detected. Such signatures can't be reliably distinguished from user mentions, and adding reply links to them would be unexpected.

The most common cause of this is someone adding a signature to an unsigned comment, but not adding the date and time when doing it. Templates like   often have a separate parameter, where you can copy the date and time from the page history.

Ambiguous "unsigned" templates
When the signature was added to an unsigned comment using a template, the template must include a link to the user page and a date and time, in this order and in the usual format, just like normal signatures.

Non-standard date or time format
If someone signs their comments with a different date or time format than the default for the wiki, their comments won't be detected.

Sometimes editors may accidentally edit another signature when adding their comments manually, breaking the format.

Another common case is a signature added to an unsigned comment without the timezone indicator (e.g. "(UTC)"), or with a different timezone than the wiki uses.

No link to the user page
Signatures must include a link to the user page, talk page or contributions of a user.

The "reply" link cannot be used to reply to this comment
You'll see this error message when the comment appears to be transcluded from another page, but the tool can't determine from which page, and therefore can't determine where to add your reply. This can be caused by:

Could not find the comment you're replying to on the page
Usually this error message indicates that someone else removed the comment from the page while you were reading it. It might have been reverted, archived, moved to another discussion page, or the signature might have been changed (e.g. if someone commented while logged out and then corrected the username, or if they expanded their comment and signed it again).

If you can still see the comment after refreshing and purging the page, and you still receive this error, it might indicate a bug in Parsoid causing it to render the page differently from the PHP parser (DiscussionTools uses Parsoid internally to add new comments). Please file a task!

Comments on this page can't be replied to because of an error in the wikitext
You'll see this error message when there is a lint error on the page caused by fostered content. Editing these pages using tools that rely on Parsoid, such as DiscussionTools or VisualEditor, can cause the content to be corrupted (large fragments of the page become duplicated).

To resolve this, you can fix the lint error in the wikitext editor. The error message includes some links that hopefully are helpful.