Updates from today 7/10 (develop) were failing to install.
The error was Update process failed: Could not find a part of the path ‘C:\ProgramData\zbDrone\Backups\update’.
After manually creating the update folder, I was able to install the updates.
There is already a thread on this subject, no more than 10 posts down: http://forums.nzbdrone.com/discussion/2322/update-not-working it is now an announcement.
Sorry, I seen it shortly after I posted.