Supressing “The certificate Couldn’t Be Verified” message Using the Microsoft Remote Desktop Application on Apple macOS

Introduction

In my previous blog post, Using the Microsoft Remote Desktop Application on Apple MacOS, I showed how easy it is to connect to one of your Windows computers from your Mac.

I frequently use the Microsoft Remote Desktop application on my Apple MacBook Pro to connect to one of my Windows computers. It presents a nice interface that’s easy to use and setup.

Once you’ve added your computer to the Microsoft Remote Desktop application (you’ll find the instructions in my previous post), all you have to do is double click on it to access your remote computer.

Here is the launching point, note that for security reasons in all of the images in this article I’ve blurred out the name of my computer and replaced it with <name>.

There is one irritating behavior. When connecting to a computer it frequently displays the following message: “You are connecting to the RDP host <name>. The certificate couldn’t be verified back to a root certificate. Your connection may not be secure. Do you want to continue?

Having to stop every time and click Continue is really annoying. Especially if you are on your home network, connecting to a computer you own and trust. There’s an easy fix though!

Suppressing the Warning Message

Simply click the Show Certificate button to display the certificate information.

Once you review, simply put a check mark in the “Always trust...” checkbox (pointed to by the arrow) then click Continue.

Since you are changing the trust certificates for your MacBook (or other Apple Mac computer, like the Mac Mini), macOS will prompt you to enter your admin password. Do so, then continue.

From here on out, all you need to do to connect to your remote computer is double click on it, and (if you’ve not saved it within the remote desktop program) enter your credentials. No more having to click to continue past the “certificate couldn’t be verified” message.

Conclusion

I’ll wrap this up with two quick notes. First, this works on the last several versions of macOS including Big Sur.

Second, while I’ve used Windows as the example, this will work with any OS (such as various Linux distros) that support RDP (Remote Desktop Protocol). Sadly, macOS does not support RDP so you cannot connect to another Mac from the Microsoft Remote Desktop application.