Never heard of the “changing media” error message.
Can you try some of the other diagnostic tools (particularly mediainfo) listed on this page
to ascertain yourself that the file is a genuine file and not a fake? gspot works with many file types (particularly avi) but it may not recognize some others (mkv for example). If it still doesn’t recognize it, I’d suspect a fake (especially given how a versatile player like VLC Media Player can’t open it).
One last test is to check if it’s another file type (CD image like ISO, archive like zip or rar). Open the file in a hex editor (try winhex) and see what the first few letters or strings are. BTW if you see nothing but zeroes, it’s definitely a fake.
Having major issues when trying to launch some of the avi files I’ve downloaded recently. Installed various apps such as dvix, vlc etc, ran gspot and getting “file unknown / 0x80040265: [unknown] message” but in codecs screen highlighted an issue with a missing file. Opened regsvr and registered the “missing” dll but no change. Same message appears. Now trying to open in MPC does nothing (ie won’t open file) and opening in Windows media Player causes message “Changing media” to appear but then seemingly hangs as it nevr completes. Anyone have any ideas?