I can't login to Lastpass, this is a very common problem for users. There is only one workaround, installing a very old version of Lastpass (but that's a security risk). Lastpass is either unwilling or unable to fix the issue. Some think it has something to do with having too many websites in your Lastpass vault. Intriguingly, Firefox appears to send data to Lastpass servers when I click Log In (seen using Wireshark), but noting happens. I have to copy my PWs from Chrome (not giving up on FF).