I run a win 10 pro 64bit pc and experienced the issue after I installed the new update.
In fact, for the first book I tried to download metadata for it searched and found them, but then displayed an error message for the cover.
Repairing, un-installing and rolling back a version, and finally re-installing did not solve the problem...
same exact issue, same exact message
I hope some clever guy solves it for the rest of us.
Thanks in advance!