If you get the error message "Please place all files from the archive into your battleforge folder."
Here is the SOLUTION that worked for me:
Don't be an idiot like me and put the .rar file into a folder with the SkylordsReborn Updater unless you have UNZIPPED it using WinZip or a similar program.
You have to download the client (4.7 GB), the Updater (8.5 MB) and WinZip
(1) Un-Zip your battleforge.rar file into any folder you like
(2) This will create a folder called "Battleforge" that is now full of a whole bunch of other files
(3) Extract SkylordsRebornUpdater into the Battleforge folder (not the parent folder)
(4) Double click the SkylordsRebornUpdater
Again, don't be an idiot like me. I imagine most of the problems relating to the error message "Please place all files from the archive into your battleforge folder." are becuase you are in idiot (like I was).