when I click the download link. 503 Service Unavailable No server is available to handle this request.
I'm assuming you're referring to the 5.4.0b13 build. The download worked fine for me, but if you're having problems you can try this magnet link: magnet:?xt=urn:btih:435ed03038afaa0b52f2594a7fe50a752aa18c7f&dn=Unity-Linux-5.4.0b13&tr=http%3A%2F%2Ftracker.unity3d.com%3A6969%2Fannounce (just paste it into your browser's address bar and it should open up your torrent client). This should allow you to start downloading with your torrent client without downloading the actual '.torrent' file.
i cant access anything on store, i cant acess proyect lower 2019.1 my account in assets store dont let me download or even sign in and it shows 503 Service Unavailable , why?