New apache config for 1.31.42 up

gistfile1.txt

#
# PLEASE NOTE THAT THIS FILE IS INTENDED FOR GUIDANCE ONLY AND MAY NOT BE APPROPRIATE FOR YOUR DISTRIBUTION
#
# This is for use with debian/ubuntu based distributions
#
# Sample configuration file for running ZoneMinder as name based virtual host
# Some values may need to manually adjusted to suit your setup
#
<VirtualHost *:80>
    ServerAdmin webmaster@localhost

    DocumentRoot "/usr/share/zoneminder/www"

    # Order matters. This alias must come first.
    Alias /zm/cache "/var/cache/zoneminder/cache"
    # IF you aren't using /zm in the url to access ZM then uncomment the following line as well
    # Alias /cache "/var/cache/zoneminder/cache"
    
    <Directory "/var/cache/zoneminder/cache">
        Options -Indexes +FollowSymLinks
        AllowOverride None
        <IfModule mod_authz_core.c>
           # Apache 2.4
           Require all granted
        </IfModule>
        <IfModule !mod_authz_core.c>
            # Apache 2.2
            Order deny,allow
            Allow from all
        </IfModule>
    </Directory>
    
    ScriptAlias /zm/cgi-bin/ "/usr/lib/zoneminder/cgi-bin"
    ScriptAlias /cgi-bin "/usr/lib/zoneminder/cgi-bin"
    <Directory "/usr/lib/zoneminder/cgi-bin">
        Options +ExecCGI -MultiViews +SymLinksIfOwnerMatch
        AllowOverride All
        <IfModule mod_authz_core.c>
           # Apache 2.4
           Require all granted
        </IfModule>
        <IfModule !mod_authz_core.c>
            # Apache 2.2
            Order deny,allow
            Allow from all
        </IfModule>
    </Directory>

    Alias /zm "/usr/share/zoneminder/www" 
    <Directory "/usr/share/zoneminder/www">
        Options -Indexes +FollowSymLinks
        AllowOverride All
        <IfModule mod_authz_core.c>
           # Apache 2.4
           Require all granted
        </IfModule>
        <IfModule !mod_authz_core.c>
            # Apache 2.2
            Order deny,allow
            Allow from all
        </IfModule>
    </Directory>
    # For better visibility, the following directives have been migrated from the
    # default .htaccess files included with the CakePHP project.
    # Parameters not set here are inherited from the parent directive above.
    <Directory "/usr/share/zoneminder/www/api">
       RewriteEngine on
       RewriteRule ^$ app/webroot/ [L]
       RewriteRule (.*) app/webroot/$1 [L]
       RewriteBase /zm/api
    </Directory>

    <Directory "/usr/share/zoneminder/www/api/app">
       RewriteEngine on
       RewriteRule ^$ webroot/ [L]
       RewriteRule (.*) webroot/$1 [L]
       RewriteBase /zm/api
    </Directory>

    <Directory "/usr/share/zoneminder/www/api/app/webroot">
        RewriteEngine On
        RewriteCond %{REQUEST_FILENAME} !-d
        RewriteCond %{REQUEST_FILENAME} !-f
        RewriteRule ^ index.php [L]
        RewriteBase /zm/api
    </Directory>
   # Use the first option to have Apache logs written to the general log
    # directory, or the second to have them written to the regular Apache
    # directory (you may have to change the path to that used on your system)
    ErrorLog /var/log/zm/apache-error.log
    #ErrorLog /var/log/httpd/zm-error.log

    # Possible values include: debug, info, notice, warn, error, crit,
    # alert, emerg.
    LogLevel warn

    # Use the first option to have Apache logs written to the general log
    # directory, or the second to have them written to the regular Apache
    # directory (you may have to change the path to that used on your system)
    CustomLog /var/log/zm/apache-access.log combined
    #CustomLog /var/log/httpd/zm-access.log combined

</VirtualHost>

I have applied the recommendations from the comments.

TheDocumentRoot in line 12 should be commented out. It is not needed and if we enable that it allows for loading the portal on "/" which breaks CSS

both ScriptAlias lines must have trailing slash for me:
ScriptAlias /zm/cgi-bin/ "/usr/lib/zoneminder/cgi-bin"
->
ScriptAlias /zm/cgi-bin/ "/usr/lib/zoneminder/cgi-bin/"