Every single time i plug my S6 through usb to my PC there's a pop up window that says "Allow access to device data. An MTP connection will be established to access the data on the connected device". Is there an option to disable this pop up?
Welcome to Android Central! I don't think so. The default on Marshmallow is Charge Only, and this notification is there to remind the user that they have to manually change to MTP if they want to transfer files.
Facebook
Twitter
Instagram