Firefox in ubuntu cli GLib-CRITICAL error

I have installed Firefox on my ubuntu server so I can run selenium testing through jenkins linked to bitbucket.

Jenkins told me that it didnt have access to firefox so I installed it with

sudo apt-get install firefox

this installed firefox version 38. the tests continued to give errors like this

org.openqa.selenium.firefox.NotConnectedException: Unable to connect to host    
127.0.0.1 on port 7055 after 45000 ms. Firefox console output:

(process:28482): GLib-CRITICAL **: g_slice_set_config: assertion 
'sys_page_size == 0' failed

Error: no display specified

(process:28489): GLib-CRITICAL **: g_slice_set_config: assertion 
'sys_page_size == 0' failed

Error: no display specified

when I check the version this error comes up to. I have fully removed firefox and installed from the tar file to version 35 since I read that this could fix the problem.

It didn't fix it, the error comes back the exact same but the version has been changed to 35.

This is the Main of script that Jenkins is running

public class Test {
protected WebDriver driver;

@Before  
public void setUp(){        
driver = new FirefoxDriver(); 
driver.get("http://www.google.com");

} //End Before

@Test

public void testGoogleSearch() { 

   // Find the text input element by its name          
WebElement element =  driver.findElement(By.name("q"));
   // Enter something to search for          
element.sendKeys("Selenium testing tools cookbook");
   // Now submit the form. WebDriver will find             
//the form for us from the element            
element.submit();

System.out.println("You have just logged into the  google6 website");

} //End of google search

@After   
public void tearDown() throws Exception {       
//Close the browser

driver.quit();
}
}//end

I don't believe the script is the problem but I thought that I would try to build a full picture.

Any help fixing this firefox error is really appreciated. Thanks