TbSync is not supported by v142 (releaseaddon)

Do you mean https://addons.thunderbird.net/en-US/thunderbird/addon/eas-4-tbsync/

You might want to switch to https://support.mozilla.org/en-US/kb/thunderbird-esr so you will be far less likely to encounter this problem.

This topic explains why TbSync doesn't support TB 142:

https://github.com/jobisoft/TbSync/issues/756

but it still works for the ESR version.

Thanks.

I downloaded and installed ESR but I received a message that since my profile was written by v142, I would have to completely re-install all of my e-mail and etc. I would rather avoid having to do that sinc, at this point, the cure is worse than the disease.

From what I can tell, Mozilla will be incorporating tbsync's functionality for linking Exchange calendar in an upcoming release. However, in the interim is there an alternative to tbsync for linking/syncing my Exchange calendar with Thunderbird calendar?

If you open TB from a Run line (Windowskey+R) like this:

thunderbird.exe --allow-downgrade

you should be able to run the ESR on the 142 profile, but a seamless transition isn't guaranteed.

I'm not aware of another way to sync an Exchange calendar in the current release version.

From what I can tell, Mozilla will be incorporating tbsync's functionality for linking Exchange calendar in an upcoming release. However, in the interim is there an alternative to tbsync for linking/syncing my Exchange calendar with Thunderbird calendar?

There is no alternative AFAIK.

Thanks. I downloaded and installed ESR but I received a message that since my profile was written by v142, I would have to completely re-install all of my e-mail and etc. I would rather avoid having to do that sinc, at this point, the cure is worse than the disease.

With ESR, on your first startup use the override https://support.mozilla.org/en-US/kb/dedicated-profile-thunderbird-installation#w_what-happens-to-my-profile-if-i-downgrade-to-a-previous-version-of-thunderbird