I normally use Firefox as my browser. Early this morning everything was normal with LastPass. A couple hours later, I could not log into LastPass from the extension. It kept telling me my password was invalid. I tried logging into Lastpass.com. The first time, I got in. But a little later, the "invalid password" was back again. I even reinstalled Firefox and still no luck.
I then tried Chrome with the same LastPass account & password and everything is OK. That leaves me wondering if the problem is between Firefox and LastPass.