Q:
Is login server down?
If it’s sticking on the download specifically, it’s probably failing to connect to your nearest asset server. You can manually try a different one using a command like this:
Gw2.exe -assetsrv drwkwiejruot6.cloudfront.net
… or you can try to bypass it entirely, if you’re up to date, using the command:
Gw2.exe -email example@email.com -password examplepwd -nopatchui