Unfortunately, I wasn't able to reproduce this problem on my 64bit Windows 10 machine. Can you please check your Java version?
I got the following results:
Code:
java -version
java version "1.8.0_91"
Java(TM) SE Runtime Environment (build 1.8.0_91-b15)
Java HotSpot(TM) Client VM (build 25.91-b15, mixed mode, sharing)
Are you using a Windows 10 VMWare/VirtualBox image by any chance or did you install Calibre on a drive other than
C:?
If you installed Calibre on a drive other than
C: could you please temporarily install Calibre on your C: drive to test whether this fixes the bug?
If it does, I'll have to update the plugin code to search for drives other than
C:.