Hi, I*have started to setup a staging website so that I*can test new implementations before going live. The staging site is in a subdomain.
The frontpage of this staging website can be accessed without problems, and it seems database and files were correctly copied.

I*modified config.inc.php and replaced the existing domain with the subdomain:
Only registered members can view the code.
and here pointed to the correct file folder:
define('RL_ROOT', '/xxx/123456/hosting/5678/6543/subdomain' . RL_DS . RL_DIR);

Also adjusted credentials for database and password...-> Frontpage correctly shows

But e.g. clicking adding a new listing button oder other links on the frontpage produces a 404 error.