I have installed Jenkins
by deploying its WAR file to Tomcat
. On typing
http://localhost:8080/jenkins
In browser
If you're using Chrome
Go to: Manage Jenkins → Manage Plugins → Advanced, then click Check now
in the bottom right-hand corner. Then click a shield icon in the address bar, click Load anyway
and Jenkins will start to update plugins. In Firefox this icon is situated on the left side of address bar, near back button.