Monica CRM – Fix mixed content (HTTP assets on HTTPS)

Installation context 
 Monica CRM was installed using the official Proxmox VE Community Script . 
 This means: 
 
 Monica runs inside a Proxmox LXC container 
 PHP, Apache2 , and the directory structure follow the community script defaults 
 Configuration changes (such as .env ) are made inside the LXC 
 HTTPS is typically terminated outside the container via a reverse proxy (e.g. Nginx Proxy Manager) 
 
 Because of this setup, trusted proxy headers and HTTPS detection are mandatory , otherwise Monica/Laravel will incorrectly assume HTTP and generate mixed-content URLs. 
 
 Problem 
 When accessing Monica via HTTPS, the browser may show warnings like: 
 
 CSS or images are loaded via http:// 
 Assets are blocked or only partially loaded 
 DevTools shows “mixed content” warnings 
 
 Example: 
 The page at https://monica.example.net requested insecure content from http://monica.example.net/…
 
 
 Cause 
 Monica (Laravel-based) still thinks it is running on HTTP , even though it is accessed via HTTPS through a reverse proxy . 
 Typical reasons: 
 
 APP_URL is still set to http:// 
 Reverse proxy headers are not trusted 
 Laravel configuration cache was not cleared 
 
 
 Solution (recommended order) 
 Follow steps in order and test. Best done after a fresh new install. 
 It could be enough to just set the APP_URL and the APP_ENV . But maybe it doesn't, then you can also try steps 2++. 
 
 1. Set correct APP_URL 
 Edit Monica’s .env file: 
 APP_URL=https://monica.example.net
 
 Important notes: 
 
 Use the final public URL 
 No trailing slash 
 Must match the reverse proxy domain 
 
 
 2. Set APP_ENV to production 
 Edit Monica's .env file and change from local to production : 
 # Two choices: local|production. Use local if you want to install Monica as a
# development version. Use production otherwise.
APP_ENV=production
 
 3. Trust reverse proxy headers (very important) 
 If the above does not work, add this to .env : 
 TRUSTED_PROXIES=*
 
 Why this matters: 
 
 Monica is behind a reverse proxy 
 HTTPS is terminated at the proxy 
 Apache receives HTTP internally 
 Without trusted headers, Laravel assumes HTTP 
 
 
 4. Clear and rebuild all caches (mandatory) 
 From the Monica installation directory: 
 php artisan optimize:clear
php artisan config:clear
php artisan cache:clear
php artisan route:clear
php artisan view:clear
php artisan config:cache
 
 Do not skip this step.
Laravel caches URLs aggressively. 
 
 5. Restart services 
 LXC / bare metal (Apache2) 
 systemctl restart apache2
 
 Docker / Docker Compose 
 docker compose restart
 
 
 Nginx Proxy Manager (common setup) 
 
 Enabled by default 
 Do not override Host headers 
 Do not force HTTP upstream 
 Remove custom proxy headers if unsure 
 
 Apache does not need special configuration for this as long as the headers are passed correctly. 
 
 7. Verify in the browser 
 
 Open the site with HTTPS 
 Hard refresh ( Cmd + Shift + R ) 
 Open DevTools → Network 
 All assets must load via https:// 
 
 Test directly: 
 https://monica.example.net/css/app-ltr.css
 
 No redirects to http:// should occur. 
 
 Summary 
 To fix mixed content issues in Monica behind a reverse proxy (Apache2 setup): 
 
 Set APP_URL to HTTPS 
 Set APP_ENV to production 
 Trust proxy headers 
 Clear all Laravel caches 
 Restart Apache and or reboot. 
 
 Once done, Monica will correctly serve all assets over HTTPS .