I've encountered this weird problem. On a site we're trying to help out on some of their URLs for attachments have become broken.
URL in post_content
If i go into the posts in question and click to edit the image, it knows the correct attachment, then it stores it correctly. It only seems to happen for images in 2016/04 from what they've been able to tel me (The site has 1000s of posts so hard to check them all)
_d_improd_ directory does exist, however it only has 4 images inside, none of which are used in any of the posts I've found. They thought this was caused by my speed updates however I reverted to my initial commit from taking their site dump and can;t find any instance of that folder name in my codebase.
Unfortunately searching the net only returns index upon index of people who haven't formatted their servers very well and Google has indexed their directories. When I can find an actual page with the folder referenced it usually someone having a problem with something else who also happened to have
_d_improd_ in their URLs for some reason, but it;s never mentioned.
Does anyone have an idea where this folder could be coming from or be caused by? I'm not looking forward to having to fix this without any idea of the cause, regexing wildly with find replaces on a 2GB database.