I tend to stay away from bundling 'beta' software/versions of anything with LXLE which is the reason Lightning 3.3.3 was enabled by default. However it seems the latest update to SeaMonkey has broken it's functionality. So anyone wishing to get it back to a working state should visit the following site.
Please keep in mind that once you install a beta version of an addon, it has a tendency to keep wanting to install beta versions. I have emailed mozilla and made a formal recommendation that point releases should be more frequent considering automatic updates to email clients and browsers. Hopefully in the future they will begin to start following the practice of updating plugins to work with what most of their users are running on their systems.
One needs to ensure that Lightbird is installed, and apparently GNOMErunner/GTK Revived. If not, the calendar cannot be invoked from the Left Side Bar of the desktop, nor the icon at the bottom of the browser, nor the menu drop down window/calendar.
Today I installed 14.04.4, with Seamonkey. I added Firefox as well. I noticed that Firefox had the same LXLE home page as Seamonkey. Is that because Seamonkey and Firefox are sharing files? Is this a conflict that I should be aware of? Or is it just awesome?