Looks like you may have had some server issues. When I first checked your site it wouldn't load. It is loading now. I'm not good at server side problems. I rely on the hosting company for help there. If you still have issues click on the link on the error page to see the details. It may give you some info on the error. You can also set debug to "true" at the bottom of the config.php file, and repeat the action on your site to see if there are any errors.

Thanks Darryl for the lightning fast response,  here is a debug I did, not sure what this Means   regards  Ben

ssage:Undefined offset: 1File:/home/sensingh/public_html/ow_system_plugins/base/bol/theme_service.phpLine:634

See capture

Not sure. You can try making sure you file / folder permissions are set correctly by following the info in this post.
https://developers.oxwall.com/forum/topic/14334

You may also want to make sure you are using minimum php version 5.5. Don't go higher than 5.6 though; they haven't tested anything higher.