Are both calendars hosted on the same CalDAV server? If so, this page may have the solution: https://sys4.de/en/blog/2014/07/11/multiple-caldav-calendars-thunderbird-lightning-auth-problem/

I went to the link you provided and not sure what I have to do

Where are your calendars hosted? Google? Yahoo? GMX? or somewhere else?

They are at other email provider its MTS email

The workaround is to set parameter calendar.network.multirealm in Thunderbirds config editor

OK not that technical how do I do that

Go to Tools|Options|Advanced|General.

Click on "Advanced" . Acknowledge the warnings.

Copy calendar.network.multirealm into the search box at the top. If the lower pane becomes empty, then this means that this preference doesn't yet exist, so we have to add it.

If it does appear, we want it set to true and double-clicking it should swap it from false to true.

If you need to add it, then right-click on the lower pane and select new then boolean. Paste it in and set it to true.

Thank you I will try it when I get home and post the result

ok I done exactly what you said and it was there and found it and set it to true. went to calendars right click went to properties and switch calendar on and it still wont work

Did you restart Thunderbird?

I did this morning it works just fine now thank you very much. lol I feel stupid about not restarting. I guess there is no contact section in thunderbird or is that hidden

beaverman1 said

I did this morning it works just fine now thank you very much. lol I feel stupid about not restarting. I guess there is no contact section in thunderbird or is that hidden

Do you mean the address book?

Yes is there one and can carddav sync with this

Also I have set this thunderbird on my personal PC can I add at work and do I have to perform the same setup or install and just sign in

Re the address book: it looks as though you may be able to sync with carddav. There's a tutorial with screenshots here: https://help.hover.com/hc/en-us/articles/217282057-CalDAV-and-CardDAV-Synchronization-for-Thunderbird That's for Hover, obviously: you will need to substitute the correct settings for MTS mail which are given here: https://www3.mts.ca/mts/support/internet/email/how+to+sync+calendar+and+contacts+with+mts+mail Re Thunderbird at work: I don't know. Your employer may well have a policy about whether or not you can install software on their machines. If you are allowed to use it and you want to see both calendars, yes you may well have to edit the config settings to see them both.

Thank you that did the trick works fine now