Are you not able to upload files via Use-your-Drive? Please check if the Upload Folder that you selected in your shortcode isn't the Google folder. This virtual folder contains your 'My Drive' and the 'Shared with me' folder and cannot be used to upload files to
To fix this issue, just and select the My Drive folder or any other folder in the My Drive folder.
If this doesn't help you, please create a support ticket and provide your purchase code and a temporarily WP admin login so we can safely debug the issue for you?.