yes, I saw the post you're referring, but in that particular case it was a message of service unavailable. In this case, the message is about not being signed in, which I'm sure I am =(. I tried the solution of that post to see if maybe it solves my problem but no success
I will cross post your message there in case they have ideas.
Hi jpv123 -
Can you try closing Adobe XD, logging out of the Creative Cloud App and then back in, and then reopen Adobe XD and try again? This typically addresses the problem.
If the problem persists, can you email me your PDApp.log file (located at the following path: /Users/userName/Library/Logs/PDApp.log)? You can send it to: firstname.lastname@example.org.
This file will likely contain an error that can help us diagnose the problem you are seeing.
We are in the process of investigating how to resolve this issue in a future release.
Can you make sure you are logged into the Creative Cloud App? It's the cloud icon in the upper right corner. Click on the settings icon in the upper right then select Preferences:
Please let us know if you were able to solve the issue.