I followed "GNSDK for Mobile Android Developers Guide" and tried to built the sample app on my android device. I specified my gnsdkClientId and gnsdkClientTag, and crated an empty license.txt file in my assets folder. The status on top of the Android sample UI still complains "gnsdk_manager_initialize: An invalide license was specified". Did I miss any step? should I put anything in the license.txt file? 


Hi Danny,
Please go to the "My Apps" page, find the license string on your App detail page and paste the whole license string into your license file.
Let me know if this solves your issue.