I also can not access 2018 & 2019...2013-2017 still allow me to login  and I can login to 2022 & 2023.

Try the new Lacerte Tool Hub https://proconnect.intuit.com/community/help-articles/help/fix-common-problems-and-errors-with-the-l...

You need to install each of those old years to update them.

Judy. Did the fix promoted in the answer below go as planned. Specifically, after implementing the recommended fix, did all of your tax data remain intact for the years you could not previously access? Thanks for any input. I simply cannot afford to lose all that data?

Again, I appreciate your help.

Tim M

Messing with the program will not mess with the data. Do the update and it will fix the issue.

Many thanks Sir. Mmuch appreciated. Tim

@THM  ".... I simply cannot afford to lose all that data?"

But you would be able to restore all your data from the backup(s) you have, right?  You DO have a back up (one, two, three ) of all your data, correct?  Either to thumb drives, to the cloud (Carbonite is a recommended one).

The Lacerte Tool Hub has a function to back up all the 'x'data info (where 'x' is the 'i' for individual 'p' = partnership, etc) to a file, and also to a zip file.  I copy those backup files to a thumb drive daily during filing season, and every day during the offseason if I work on tax returns.  That thumb drive (which yes, is encrypted) travels with me everywhere.

I am unable to access my 2020 Lacerte Tax programs

@CurJax 

Did you follow George's suggestion to use the ToolHub to force a re-install of the software?

Everyone was supposed to update prior years by 12.31.23.  But many (including myself) that did that still had to reinstall the programs. 

And no, your data isn't impacted.  But you have good backups anyway, right?

 This is from @PhoebeRoberts in another forum for another year, but it MAY apply.