diff --git a/Installation.md b/Installation.md
index ccf5c16..c2531a3 100644
--- a/Installation.md
+++ b/Installation.md
@@ -62,6 +62,11 @@ If you get an error "403 Forbidden" / "404 Not Found" / "The requested URL was n
 - Check that the directory has the **correct file permissions** (`chmod -R 755 /var/www` + `chown -R www-data /var/www`) especially after moving files across servers. Files owned by root cannot be read by the web server.
 - Check that you've extracted it to the correct directory (if the "public_html" folder exists, extract to that folder)
 
+If you get an error "502 Bad Gateway":
+- Check your web server's error logs (e.g. `/var/log/nginx/error.log`) for the full error message.
+- This usually indicates that your web server hasn't been set up correctly for PHP.
+- Under Nginx the most common problem would be that the path to `/var/run/php/php*.*-fpm.sock` under `fastcgi_pass` in `nginx.conf` hasn't been specified correctly. Check that this file exists, and that the version number of this file in `/var/run/php/` matches the configuration's version.
+
 If you get **redirected** to the wrong page when trying to access bans (e.g. Multicraft admin panel instead of the web interface):
 - Set up different subdomains for each web installation you have, instead of putting everything on the same domain/subdomain.
 - Also set up different virtual-hosts for everything that should be installed separately, if needed. Each web package should get its own directory to prevent conflicts.