When I try starting Apache from the XAMPP control panel (Mac OS X 10.6.8 Snow Leopard), I get the following error popup and Apache won’t start:

```
/Applications/XAMPP/xamppfiles/bin/apachectl: line 70: ulimit: open files: cannot modify limit: Invalid argument
(48)Address already in use: make_sock: could not bind to address [::]:80

```

XAMPP was running perfectly 10 minutes earlier. I stopped Apache to add some `.conf` files and it failed on restart. I removed all the new `.conf` files (i.e. reverted it to how it was before) but now I get the above message.

I’ve checked AppMonitor and I see the `httpd` processes (one by `_www` nested within root). Just tried quitting these but they’re auto-restarted on new process IDs and it didn’t solve the problem.

And I’ve tried a full reboot and I still get the same error (before starting any apps). I’d be grateful if someone has an idea how to solve this.