I am using Mac Catalina and X-Plane 11. Logged on today and received an update request for Simlink which I did. Now I get a window telling me that Simlink cannot be opened because of a problem.
I have logged in to my Navigraph account and downloaded the lates Simlink again but still get the same issue.
I am having exactly the same problem with a MAC running Mojave when trying to start Navigraph Simlink. Looks like a problem related to my Mac OS version.
Here is the beta test version for those facing the issue of Simlink not working on older macOS versions like Big Sur, Mojave and Catalina.
Please let us know if you are facing an issue with it.
Please uninstall Simlink completely and install it again from the Beta link. It looks like there are still some components that exist which are not supported by Mojave.
Here is a screenshot for Simlink beta works with Mojave macOS.
We are a step closer. Simlink opens on my iMac and I get the same information as you do in your window below except of course I am using X-Plane 11 on Mac OS Catalina version 10.15.7. So whilst Simlink now opens and I get the Navigraph Simlink Status box, it does not connect to my simulator!