GeckoDriver Selenium; desired capabilities error -

i using selenium using geckodriver , selenium-3.3.1. whenever run tests keep getting firefoxdriver error. know cause or meaning this?

1491438811062   geckodriver info    listening on 127.0.0.1:41173 exception in thread "main" org.openqa.selenium.sessionnotcreatedexception: unable create new remote session. desired capabilities = capabilities [{moz:firefoxoptions={binary=optional.empty, args=[], legacy=null, loglevel=null, prefs={}, profile=null}}], required capabilities = capabilities [{moz:firefoxoptions={binary=optional.empty, args=[], legacy=null, loglevel=null, prefs={}, profile=null}}] build info: version: '3.3.1', revision: '5234b32', time: '2017-03-10 09:04:52 -0800' system info: host: 'andy-pc', ip: '192.168.0.6', os.name: 'windows 8.1', os.arch: 'amd64', os.version: '6.3', java.version: '1.8.0_51' driver info: driver.version: firefoxdriver     @ org.openqa.selenium.remote.protocolhandshake.createsession(protocolhandshake.java:126)     @ org.openqa.selenium.remote.httpcommandexecutor.execute(httpcommandexecutor.java:141)     @ org.openqa.selenium.remote.service.drivercommandexecutor.execute(drivercommandexecutor.java:82)     @ org.openqa.selenium.remote.remotewebdriver.execute(remotewebdriver.java:604)     @ org.openqa.selenium.remote.remotewebdriver.startsession(remotewebdriver.java:244)     @ org.openqa.selenium.remote.remotewebdriver.<init>(remotewebdriver.java:131)     @ org.openqa.selenium.firefox.firefoxdriver.<init>(firefoxdriver.java:218)     @ org.openqa.selenium.firefox.firefoxdriver.<init>(firefoxdriver.java:125)     @ org.openqa.selenium.firefox.firefoxdriver.<init>(firefoxdriver.java:121)     @ selenium.webdriver_singleton.getinstance(webdriver_singleton.java:16)     @ selenium.core.<init>(core.java:32)     @ selenium.core.main(core.java:46) picked _java_options: -xmx512m 

thanks.

you need provide firefox binary location. check out link on how set up.

http://www.automationtestinghub.com/selenium-3-0-launch-firefox-with-geckodriver/