The ReticleOS release 4.1.x (Android 6.0.1) changes slightly the way that MTP is enabled. It can be done via System Settings->Developer Options-> Select USB Configuration, but this does not persist. A quicker way to do it if via Notifications.
On Marshmallow, each time you connect USB, if you want the glasses to show up as a MTP device, you need to go to Notifications, and enable MTP like so. Steps:
- Press Menu button, select Notifications:
- Select USB for Charging (Touch for more options); This pops up this dialog:
- Select File Transfers; This will enable MTP.
- On Macs, you'll need Android File Transfer installed to see the glasses; Windows and Linux hosts handle MTP natively.