Selenium Script is failing with error in org/apache/commons/lang3/tuple/ImmutableTriple when I do driver.get(url)?

Hi, I'm using Neoload 5.2 with Selenium 2.53 and FirefoxDriver.

My script runs fine if I set the argument "-Dnl.selenium.proxy.enabled=false" in command prompt and Neoload.
But when I remove this argument in Neoload, my script returns the following error when finishes loading the URL (after loading page given by driver.get(url);):

######### ERROR ##########

DEBUG: Connection released: [id: 11][route: {}->http://127.0.0.1:7055][total kept alive: 0; route allocated: 0 of 2000; total allocated: 0 of 2000]
==== ERR ====
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/lang3/tuple/ImmutableTriple
at com.neotys.rest.dataexchange.client.DataExchangeAPIClientFactory.newClient(DataExchangeAPIClientFactory.java:107)
at com.neotys.selenium.proxies.helpers.SeleniumProxyConfig.initializeDataExchangeAPIClient(SeleniumProxyConfig.java:239)
at com.neotys.selenium.proxies.helpers.SeleniumProxyConfig.getDataExchangeAPIClient(SeleniumProxyConfig.java:205)
at com.neotys.selenium.proxies.helpers.EntryHandler.sendData(EntryHandler.java:101)
at com.neotys.selenium.proxies.helpers.EntryHandler.sendEntry(EntryHandler.java:75)
at com.neotys.selenium.proxies.helpers.ProxySendHelper.sendAndReturn(ProxySendHelper.java:189)
at com.neotys.selenium.proxies.WebDriverProxy$1.invoke(WebDriverProxy.java:78)
at com.sun.proxy.$Proxy2.get(Unknown Source)
at com.<myPackage>.login(MyClass.java:69)
at com.<myPackage>.MyClass.myMethod(MyClass.java:43)
at com.<myPackage>.Main.main(Main.java:6)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.lang3.tuple.ImmutableTriple
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 11 more