Start Application not working in 4.6

I have a working webUI test case:

When I add start Application as a Mobile Keyword then the test fails.

Error:

Unable to start app at: ‘’ (Root cause: java.lang.IllegalArgumentException: The application file is missing. Please set the application file and try again.)

Log:

06-07-2017 03:07:56 PM - [START] - Start Test Case : Test Cases/Home
06-07-2017 03:07:57 PM - [INFO] - Evaluating variables for test case
06-07-2017 03:07:57 PM - [START] - Start action : startApplication
06-07-2017 03:07:57 PM - [FAILED] - Unable to start app at: ‘’ (Root cause: java.lang.IllegalArgumentException: The application file is missing. Please set the application file and try again.)
06-07-2017 03:07:57 PM - [END] - End action : startApplication
06-07-2017 03:07:57 PM - [FAILED] - Test Cases/Home FAILED because (of) Unable to start app at: ‘’ (Root cause: java.lang.IllegalArgumentException: The application file is missing. Please set the application file and try again.)
06-07-2017 03:07:57 PM - [END] - End Test Case : Test Cases/Home

Please advise.

 

 

Ok so further research shows that WebUI tests can not also be MobileUI (Native App) tests. From what I want to do it would make more sense to enable Remote Driver and leverage Sauce Labs or Browser Stack or CrossBrowserTesting.