If you use Google Chrome, v42 will soon arrive on your computer. This version disables the Java/JRE plugin by default. So some web applications will no longer work unless you manually enable NPAPI. However, this is a short term fix as Chrome will remove support for NPAPI in September 2015. So if you use any website that relies on Java to function, you'll need to use another browser (IE, Firefox, Safari).

Chrome starts pushing Java off the Web by disabling plugins
The Netscape-era NPAPI is now off by default in Chrome 42.