I did not have this problem before I installed lightbird.

You should contact the LightBird author.

I did something I should have done before. I disabled LightBird and then tried to create an event from the email with the calendar within Thunderbird. The same thing happened. So maybe it isn't LightBird but the latest update of Thunderbird

Is the calendar set to Read Only. Right click the calendar in the Calendar Pane on the left. Select Properties.

Read only is NOT checked. In other words, it's read/write

I would be tempted to uninstall Lightning and reinstall it. The program is separate from your data so you should not lose any event data.

I'll try that and let you know. Thanks

Ok, I disabled and removed Lightening. Then after closing and opening Thunderbird. I reinstalled Lightening. The problem still exists.

Now because my computer crashed an I had the computer overhauled, this is a new instillation of Thunderbird. Is it possible that something went wrong with the install of Thunderbird. Should I delete Thunderbird and reinstall?

You could try. The same data/program separation exists with Thunderbird.

Ok, I uninstalled Thuderbird, Lightening and other add-ons

I restarted the computer and downloaded and installed Thunderbird

I downloaded Lightening. Restarted Thunderbird.

Problem still there.

Any other suggestions? Since the home page of Lightening is on Mozilla, there doesn't seem to be a way to contact the developer.

I am pretty sure that Thunderbird is also the developer for Lightning. Maybe someone else will have an idea. I am not sure of anything else to suggest.

thanks for your time. I appreciate it

If there are any other add-ons than Lightning, try to disable them. Does the problem still occur?

If this is a network calendar you can try to delete it, restart Thunderbird, and re-create the calendar.

Ok, disabled all addons except Lightening itself. The problem still occurred. The calendar is a personal one, not network.

One interesting thing happened yesteray, however.

I got tired of not being able to get me event posted, so I opened a new event manually in Calendar. Then, I right-clicked on the email that had the event. A second new event opened; this one with the event information and the save and close box disabled..

I copied the event information from the converted new event to the manually opened new event and saved the manually opened event. When I went back to the Thunderbird screen, the converted new event whisked away as if grabbed by a vacuum cleaner.

So that information might help the developer to figure out what's wrong. The fact that the converted new event seems somehow connected to the manually entered one suggests to me that there is a glitch somewhere in the coding.

Thanks for your suggestion. I really appreciate, christ1, the time that you and airmail have spent trying to help me.

Now,, how do I get this information to the developers?

Now,, how do I get this information to the developers?

You'd need to raise a bug in Bugzilla. https://bugzilla.mozilla.org/