can't turn on open directory in the server app

You have to set up DNS first.

If DNS services aren't properly configured and operating correctly, then various other parts of the OS X Server environment tends to be somewhere between flaky and unstable.

To verify DNS is working correctly, launch Terminal.app from Applications > Utilities and issue the following harmless diagnostic command:

sudo changeip -checkhostname

You'll need to enter an administrative password for the sudo, might see a one-time message about the use of sudo, then see some configuration information, and then an indication that no changes are required, or that there are issues with the network or with local DNS services. This tool will spot most local DNS and network errors, but will not spot an erronous configuration using the .local top-level domain; don't do that.

If you do not have another DNS server on your local network — the screen shot shows DNS isn't running locally, but it's possible there's another DNS server in use. If you do not have a local DNS server (and you're on a NAT'd network) here's how to set up DNS on a NAT'd network — DNS is essential for proper operations of OS X Server, and on a private NAT'd network, that's only possible with your own DNS services. You cannot successfully reference off-network DNS servers here (not the DNS servers at your ISP, nor at Google, and not via a low-end firewall that might have a DNS resolver, etc), as these off-NAT'd network DNS servers do not return the necessary IP-address-to-domain-name translations necessary for your hosts. These name-to-address and address-to-name DNS translations are part of distributed authentication and network encryption.

Hi leeham_42,

were you able to solve your problem?

MrHoffman,

my DNS server was set up by myself earlier and worked fine before.

But now it works not anymore

I checked if the DNS server works fine.

Everthing seems to be success.

But still no changes in the wizard :-)

If DNS does not work, then DNS must be repaired. To verify DNS, launch Terminal.app from Applications > Utilities and invoke the following harmless diagnostic command:

sudo changeip -checkhostname

You'll need to enter an administrative password for the sudo, might then see a one-time message around the use of the sudo command, should usually then some configuration data displayed, and then an indication that no changes are required, or that there are DNS or network issues to be addressed.

The following assumes a NAT'd network configuration: do not use .local nor .arpa as the top-level domain (TLD) of your local DNS services configuration.

Yes, I've mentioned that command before, and you might have run that command, but you did not specifically state that you have run that command. It's unfortunately far too common for folks to have DNS configuration errors. Bad DNS configurations will hose Open DIrectory. If DNS isn't working, little else will be working — and assuming a NAT'd network, you cannot successfully reference any off-network DNS services for your local network-private translations. Only local DNS servers.

Also check the Console.app from Application > Utilities, and see if there are any relevant messages being logged there from Open Directory or other services.