Device Farm Parsing Error

I am trying to send to the AWS Device Farm a test Suite with 2 Test classes and I'm receiving this Parsing Error message.

This is my testng.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE suite SYSTEM "http://ift.tt/19x2mI9">
<suite name="Default Suite">
    <test name="test">
        <classes>
            <class name="TestClass"/>
            <class name="TestSingleUrl"/>
        </classes>
    </test>
</suite>

And this is the error message I'm getting:

Failed to generate the test suites Data Provider Annotation Method Found: public java.util.Iterator TestClass.createData() throws java.io.IOException [TestNG] [ERROR] Cannot instantiate class TestClass

I ran the test in my local device, and it is working well.. I just change the driver to a RemoteWebDriver when I send to Device Farm