Uploads, installs and displays correctly
That's good, because I wasn't sure if it worked in 4.5.1.
but it always shows "0",
You need to enable Statistics in Global Configuration. Go to
Site->Global Configuration and click the
Statistics tab. Set Statistics to
Yes and
save. This will enable hit tracking.
and below it says "What's This"...
hmm... it should say Get this?
That should do it.