No display in Montage - or ability to see recordings

[DinghySailor]

I am using ZM 1.32.3 on Ubuntu 18.04, and I really like the new interface - so much easier to manage than earlier versions.
However, I still have a problem!
In the montage display, I cannot see any of my three cameras (two are IP cameras, and one is directly connected to the PC).
I am able to capture images from each camera - but I have yet to be able to capture video.
I am also unable to review captured images, so the only way to review is to go into the directory using a file browser.
However, I may have an idea as to what may be awry, but seek some guidance.
Under Options|Servers, there are three columns - "Path To Index", "Path To ZMS", and "Path To Api", with the details being "/zm/index.php", "/var/lib/zoneminder/cgi-bin/" and "/zm/api".
When I did a search for index.php, the best candidate was "/usr/share/zoneminder/www/index.php", the closest to the ZMS directory is "/var/lib/zm/", which is empty; and I didn't have a clue as to where "/zm/api" would be, as there wasn't a root folder called "/zm".
I also read that apache's httpd.conf file should have a ScriptAlias entry pointing to the ZMS location, but I run Apache2, and the apache2.conf file in /etc/apache2 hasn't got a ScriptAlias entry.
I looked at the log files, which refer to a "help" page, which does not seem relevant for ZM v.1.32.3.
If someone could help, I would be most appreciative, as I have run out of ideas as to how to fix this!
Many thanks,

[SkippyDo]

What documentation did you use for your install?

Might be an underlying directory link level issue.