Server settings in general within the discussion of this topic, are any configurations Oxwall platform can't control. Those configurations are there before Oxwall is installed and are applied to Oxwall once it is installed.
Incorrect installation - usually when connection gets broken with the server in the middle of installation.
>>>If your script really checks
permissions, than it should alert this problem with some message and not - 500 error...
orela, 500 error appears not only during installation. In fact, most of the times it appear either during core updates, plugin update/installations. So showing the real error is not really a good idea. Site users/visitors will just get shocked to see a long list of errors, exceptions, notices instead of the site they wanted to enter. Therefore Oxwall hides error page under 5oo phtml page. Site admin can enable DEBUG mode to see the real error.
Please also note that there are two types of 500 errors And only one of them is generated by Oxwall. You can read more about this here:
http://www.oxwall.org/forum/topic/4661
Eddie if you are still facing issues with Oxwall Installation, you can create a topic under
Installation Troubleshooter and Server setup .