Lightning plugin not compatible with Thunderbird 60 SOLVED

For some reason compatibility issues arise with the latest version of Thunderbird and the Lightning calendar plugin. To resolve this you can follow these steps:

Uninstall the Lightning add-on
Exit Thunderbird
Run the following command `sudo apt install xul-ext-lightning`
Open Thunderbird and click on the calendar icon on the top right

Your calendar should now show up.

All credit to the folks over at this post.