Yesterday I downloaded WoW Cataclysm and I got this Cannot stream required archive data message.The thread http://forum.warmane.com/showthread....d-archive-data didnt help at all.Wotlk and Mop are working fine and when I had cataclysm 2 months ago it worked also good.Also tried to download that version that downloads while you play but still getting the message.Am I missing something?
This error could be due to your firewall / antivirus, or your client not having the full data (if using WoD customizations).
Also, you can try downloading the full client from the website.