Sorry to hear about the trouble. Could you please try the steps below and share check if you are able to open cloud document:
Sign out of Adobe XD and Adobe CC Desktop App.
Please close CoreSync Process and all Adobe related processes from the Task Manager.
Sign back in on Adobe CC Desktop app and launch XD from there and check if you are able to open cloud docs.
If it still doesn't work, please share a few more details like:
A screenshot of the About XD info page under the he...