On-line help not installed in LO

I have recently installed LO on a current Win 10 box. The checksums for both the program and help pack files are valid. The program installs and runs fine. The help pack appears to install correctly but when I try to access help from within the program it is announced that the built-in help is not installed. Any suggestions about how to troubleshoot this will be appreciated.

Why will my offline help not work - see comments

It is a 64 bit system.