Why doesn't LibreOffice appear in LaunchPad or Finder on a Mac

It sounds like Libre Office is not in the Applications folder, but is still in the installation file. Please confirm. If it is not in the Applications folder, then drag it from the download file (.dmg) into the Applications folder. Then everything should work as you expect it.

https://www.libreoffice.org/get-help/install-howto/macos/

P.S. You should drag the LibreOffice app from the Applications folder (once you've copied it there) to the dock (the "bar") to get that working properly. I suspect the trouble occurred because you dragged the app icon from the installer directly to the dock.

Hi there, MarkPA2!

Thanks for reaching out to the Apple Support Communities! It sounds like you have an issue with your software for LibreOffice not showing in Launchpad or Finder on the Mac, but working fine from the Dock. We recommend taking a look at this article with steps to follow for How to use safe mode on your Mac. This will perform checks and stop certain software from starting up automatically. Once you are in safe mode, test to see if you have the same issue.

Also, check out this article with steps for How to test an issue in another user account on your Mac to create a new user and test the issue in the new account to see if the issue is user specific or system wide. 

Let us know the results and have a great day!

MarkPA2:

Try looking in Applications: from the Finder menu, choose Go -> Applications.

Note: Macs do not use the ".exe" extension.