Sorry to hear about the trouble. Please try the steps shared below:
Sign out of XD and CC Desktop app.
Close CoreSync and all Adobe related services from the Task Manager/Activity Monitor.
Sign back in on the Adobe CC desktop app and launch XD from there.
Once launched, please try opening the file.
In case if it still doesn't work, please share a few more details like:
The version of XD & OS.
Is this happening with a specific file or multiple files?
Is it a cloud file or a loc...