Using [superuser.com][1]'s interface tonight, was given the below error when putting together https://superuser.com/questions/588325/windows-7-in-compatibility-mode-options-on-windows-7-enterprise: ![](https://i.sstatic.net/BOzz5.png) Problem being, it was a PNG I was trying to upload. Opening it (successfully) in Windows Server 2008's mspaint.exe, and resaving as a JPG allowed upload, but what was the problem with the PNG? File can be found at http://wikisend.com/download/128434/Windows_7_Compatibility_Dialog.png apparently until July 26, 2013. Are there any logs that can be checked for a possible bug, or could this message be clarified to state what about the PNG is non-complaint, should this be the case? [1]: http://superuser.com