HTTP authentication requested on a thread? huh?

I just went to visit a thread on my Ice Cream Forum and a HTTP authentication dialogue box popped up with

(with fields for username and password)

Anyone else seeing this at weird Japanese ice cream flavor list - Ice Cream Forum or is it just me? My first guess was that someone had posted a picture that the owner later password-protected, but I managed to scroll down behind the dialogue box and didn't see any images in the posts. Any idea what could be causing this?

 

Do you have an htapassword in your htaaccess file?

Something is calling for a username and password

 

No, and that isn't my IP address either.

Edit: tried editing the posts to see if there were any images I couldn't see, but the editor wouldn't display... the animated circle spun but the edit box didn't appear.

 

Yep, I'm getting that same box. My guess would be an image in one of the posts. Have you grabbed the postids? If you can't edit it via your page, you may have to do it via the database.

 

this usually appears, when users posted images from another server who has protected his directory after the images being posted.

solution: check for broken images on this site and remove them from the posts.

i once had the same problem when i shut down my forum due to site construction work and many other admins contacted me because many users linked images from my site on their forum and everyone got this auth box.

 

I figured out which post it was and edited it in phpmyadmin. Looks like it's all better now, thanks everyone.