Rated 5 out of 5 stars

Crashes TB 24.6.0 every time I try to install it.

Edit: The beta version fixed the crashing on install.

This review is for a previous version of the add-on (1.0.5.09.1-signed.1-signed.1-signed). 

FF crash fixed in 1.0.6.6

try to install http://hcalendar.googlecode.com/files/hcalendar1.0.6.6-fx%2Btb.xpi (see details http://hcalendar.blogspot.co.il/2013/12/mozilla-extension-hcalendar-version.html)