By default, Selenium starts the browser with a fresh profile every time,
which means that it has no plugins installed. On quitting, it deletes that
profile again, to make sure that it won't slowly consume your disk.
When you start the firefox driver instance, you can ask it to load profile
Using GWT 2.4.0, Eclipse Kepler, Firefox 25.0, JDK 1.7.0_40, TestNG 6.8.5
When I run my test suite against the GWT app running on a Tomcat server,
all is well.
When I try to run it against a local copy running in Eclipse, instead of
bringing up my application, Firefox gives me: