I'm adding to this thread as I had the same issue and found a solution.
In my case no files would export and xd would either crash or say that there was an error exporting. I found that the folder I was trying to export to was marked as read only in windows. I tried to unmark it as read only but it kept resetting back no matter how many times I tried.
It was the Ransomware protection feature that was protecting my folders, meaning that xd couldn't write to a read only folder. To fix this you either have to turn off Ransomware protection in Windows (or your anti-virus software) or add xd as an allowed program so that it can write to protected folders.
I hope this helps someone as it was a very frustrating problem!