I am having trouble with a Logitech R800 presentation clicker with my new Macbook Pro. I have used the R800 for years on my older mac with USB slots but now that I have to use an adapter, the clicker is not functioning.

You did not answer my question. Does logitech say the device is compatible with your hardware? It matters not that you used it on your old hardware. From your initial post are you not having the issue on a new computer?

From the Logitech site:

System Requirements

PC

• Windows Vista®, Windows® 7, Windows 8, Windows 10 or later
• USB port

Does logitech say the device is compatible with your hardware?

PT Jones wrote:

On their website it says that it will work with a Mac. It does not list it as compatible.

Sorry I can't find that on their website. I think if it is not working and LogiTech says it will work with your hardware you should have them troubleshoot with you.