Selenium error on 2.44

I got error while testing working site. The error is as follows :

Exception in thread "main" java.lang.RuntimeException: Could not start Selenium session: Failed to start new browser session: org.openqa.selenium.server.RemoteCommandException: Error while launching browser

at com.thoughtworks.selenium.DefaultSelenium.start(DefaultSelenium.java:109)

at st4.abcd.main(abcd.java:19)

Caused by: com.thoughtworks.selenium.SeleniumException: Failed to start new browser session: org.openqa.selenium.server.RemoteCommandException: Error while launching browser

at com.thoughtworks.selenium.HttpCommandProcessor.throwAssertionFailureExceptionOrError(HttpCommandProcessor.java:109)

at com.thoughtworks.selenium.HttpCommandProcessor.doCommand(HttpCommandProcessor.java:103)

at com.thoughtworks.selenium.HttpCommandProcessor.getString(HttpCommandProcessor.java:272)

at com.thoughtworks.selenium.HttpCommandProcessor.start(HttpCommandProcessor.java:234)

at com.thoughtworks.selenium.DefaultSelenium.start(DefaultSelenium.java:100)
... 1 more