Can´t click on some websites

Hallo,

My problem with Firefox is, that sometimes I can not click on bottons on a website or scroll down menues do not open. When I try it with a different browser it works. An example is, when I try to log into my google (Gmail) account. I click on the top right button to sign in. Then I enter my email adress. After entering my email adress I try to click on continue but it is just not going to the password entering site. It´s not taking my click.