I was facing the same issue today, and I have found a fix that worked for me
Whenever you get this error, it usually says the name of a certain file that the launcher have failed to download and got stuck at, for me it was some .UPK.ZIP file, all i did from there was locate that file in the BnS directory
go to the BnS directory and then to $Patch$ > Patch > Zip > contents > bns > CookedPC > locate the specific file its getting stuck at and delete it, restart the launcher again and it worked perfectly from there.
Give it a try, I hope it helps someone out there.