OK one last duty for you and then ill see about looking things over for you. On the right side of this page is the list of requirements.
https://developers.oxwall.com/hosting
please verify that your server meets these specs.
Some of that stuff you can find in your phpinfo() report. The reason i want you to do this part is so you can learn because you will need to know how to do this.
So to do a phpinfo listing here is the fastest way.
edit your ow_includes/config.php file and AFTER the <?php at the top put this code
phpinfo();
exit;
then save it and load your site, you should get a long report appear on the screen. Keep that on the page and go back and remove that code you added and resave that file.
What you are trying to do is to display the report quickly and then remove the code fast so that if someone else loads the site they dont see the report because well you dont want the bad guys seeing that info.
Once you have that info on the screen dont close that tab because you cant get the report back unless you add the code again so just leave that tab alone.
Now you want to go down that list and see if your server meets those specs.
Myself or ArtMedia can walk you through it if you have questions were to find the stuff, but the first thing is to get the report up so you can see it.
go get um.... and let us know when you have the report up.
Now since your site currently has an error (i dont think that matters it should still work for this) it might not depending on the issue. Just let us know...