Your data is separate from the program. Just install it.

Thanks, @Airmail! Reinstalling worked.

One of the primary facilities of an email program is it's calendar, why is it that lightning or its equivalent is not amalgamated permanently with Thunderbird?

Clifton there are just as many people that come here and ask how to remove Lightning.

How hard is it to just install it and get on with your life?

I don't understand your answer, Airmail. Why would you want to uninstall the calendar? I don't hear of people having the same issue whilst using MS Outlook or the Mac equivalent.

My problem I had was that at the time i could not install Lightning as I was on a beta version which Lightning at the time was not compatible with, hence the question as to why Lightning is not part of the main program. If it was then we could assume that it would always be in sync.

That's all.

Clifton this thread is not yours and it is solved. Open your own for any questions you have. And the point of beta software is to find bugs. Do not run it if you cannot deal with them.