Crashes Firefox 28 Rated 1 out of 5 stars

Version installed on older Firefox still works on Firefox upgraded to 28. But won't install on a new computer running Firefox 28. Failure to install rates zero.

That fixed it. Thanks. back to 5 stars.

crash fixed in 1.0.6.6

fixed in http://hcalendar.blogspot.co.il/2013/12/mozilla-extension-hcalendar-version.html