"Failed to download a required update. Please check your internet connection and try again."
My internet connection was working fine however..
After I got this message I left my computer on for many hours and even over night to see if maybe it would eventually work, but nothing happened.
I am using a 64 bit Windows 7 machine, my friend whom I play with and live with also has a 64 bit Windows 7 machine and they turned WoW on and started the optimization and seen the 0% screen but then walked away(so they don't really know what happened after), and when they came back maybe 7 hours later everything was finished and WoW was ready to play, so I do not know why I am having this issue with practically the same setup and on the same internet connection.
I followed the suggested steps of turning the router/modem off and on, connecting the computer directly to the router, I turned off the firewall and such, I have ran WoW as the administrator, and still I get the same error.
This is frustrating, what should I do now? I tried to search for this problem but mostly can only pull up people complaining about it saying it is at 0% for hours, but then jumps up to complete suddenly.