USB-C not reading USB-c thumbdrives

Hey, Neil!

Thanks for visiting the Apple Support Communities. If I understand your post, you are unable to get USB-C devices to connect with your MacBook Pro with Touch Bar. I'm happy to help!

There could be a number of reasons why your devices aren't being seen with the USB-C drive. While a problem with the MacBook Pro and/or its port is possible, there are other possibilities we should explore first. I'd recommend going through the following steps, testing between each to see if the issue is resolved:

1. Check to make sure you have your Finder and Desktop settings to show connected drives: Customize the Finder toolbar and sidebar on Mac - Apple Support.
2. Use Disk Utility (About Disk Utility on Mac - Apple Support) to verify the file format of your thumb drive(s) is compatible with macOS: File system formats available in Disk Utility on Mac - Apple Support.
3. If necessary, format your drive(s): Format external drives to Mac OS Extended before using with Aperture - Apple Support specifically discusses use with Aperture, however the format steps are the same for any intended use with macOS.
4. Reset the SMC: How to reset the System Management Controller (SMC) on your Mac - Apple Support.

Additional information and support may also be found in If a USB device doesn’t work with Mac - Apple Support and Check your device’s USB connection to Mac - Apple Support.

Have a great day!