Sorry to hear about the trouble, we'll try our best to help you with it. Could you please try the steps shared below:
Sign out of XD and Adobe CC Desktop app.Close CoreSync and all Adobe related processes from Task Manager/Activity Monitor.Sign back in on Adobe CC Desktop app and launch Adobe XD from there and check again if it works or not.
If this doesn't help, please share a few more details like:
A screenshot of the About XD info page.The version of the Operating System.Are...