Unable to install LibreOffice_6.0.1_Win_x64_helppack_en-US

During the installation I’m told an msi file is needed uninstall the old version of helppack. The version needed is 5.4.2.
It’s not on my system and doensn’t appear to be on your download folder.

What’s my next move?

Grab the old one from Index of /libreoffice/old

The install will not accept or and there is no 5.4.2 version there. Which is the version being demanded (apparently). Makes one want to go back to the days before .msi files sullied the landscape. is the one that was released as 5.2.4. You should make sure that you download the x64 version (as your title suggests). If you still have the problem, you could try MS tool for resolving problems with Windows Installer.