User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20100101 Firefox/12.0 Build ID: 20120420145725 Steps to reproduce: In our custom Flash video player, we try to open a 2.9GB MP4 file (pseudostream). Actual results: Flash cannot open the file and fires a NetStream.Play.FileStructureInvalid exception. You can reproduce this bug up to 15a1 (nightly for Windows), even with Firefox x86-64 15a1. Expected results: Flash should access the file correctly. It works under Opera & Chrome with the exact same plugin. Other files <2GB works perfectly. Might be related to bug 215450. The URL of the video is http://online.nolife-tv.com/emission-30154 but you need to be logged in & have a "soutien" subscription to be able to access the file through the highest video quality ("TV"). We can create a few test accounts if needed.