Xamarin building IPA error

I did not find what was causing the build error for the IPA. My app was an universal app, I re created an app as iPhone only and it worked.

Server returned an error. The remote server returned an error: (500) Internal Server Error.
Server error code: 500
Internal Server Error
<?xml version="1.0" encoding="utf-8"?><mtbs xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"><payload type="generic" code="Error" exitCode="0" serverStatusCode="200"><messages><message>InfoPlistBuilder failure during build
Exception thrown: Object reference not set to an instance of an object</message></messages><async>false</async></payload></mtbs>

Remote build step failed.

 Build Error while Building Adhoc IPA