Factorio Forums

For some reason the Ideas and Suggestions forum always shows as having unread posts for me, even immediately after marking all topics and subforums read. Going into the forum confirms that none of its subforums show unread posts, and none of the announcements or posts on the first page are unread.

Check the unread posts list if there really are no unread posts in the forum:
search.php?search_id=unreadposts

If it still shows it as unread then go to the forum and click both Mark subforums read (above the subforums) and Mark topics read (after the last thread in the list). This should clear all unread flags.

As I said in my first post, it shows as unread even after clicking both "mark topics read" and "mark subforums read". I did manage to get it to go away by going to the forum's main index and clicking "mark forums read".

Cannot reproduce.
Did you refreshed the page after going back?

I did.

I've come up with a hypothesis for what might be happening, though. If I look at the "Factorio Direction" forum, it has three subforums: "Development Proposals", "Ideas and Suggestions", and "Balancing". "Ideas and Suggestions" then has three subforums of its own: "Frequently Suggested/Link Collections", "Implemented Suggestions", and "Outdated/Not Implemented". If I go into the advanced search menu and look at the "Search in Forums" box, it shows "Factorio Direction" as having two subforums: "Development Proposals" and "Ideas and Suggestions", with "Ideas and Suggestions" having five subforums: "Frequently Suggested/Link Collections", "Implemented Suggestions", "Outdated/Not Implemented", "To be sorted", and "Balancing".

Is it possible that the read/unread icon is selected based on the search function's directory tree? If so, "Ideas and Suggestions" might show as having unread posts when "To be sorted" (does this still exist? I can't locate it) or "Balancing" has unread posts even though "mark subforums read" only affects "Frequently Suggested/Link Collections", "Implemented Suggestions", and "Outdated/Not Implemented". It should be simple enough to test, it just needs an unread post in Balancing to check it against.

Edit - looks like that's not it. I can't reproduce it any more, so I guess it will probably remain a mystery.