500 errors usually mean that the server has encountered an unexpected condition that prevented it from fulfilling the request made by the client. This is a general error class returned by a web server when it encounters a problem in which the server itself can not be more specific about the error condition in its response to the client.
In many cases this is not an indication of an actual problem with the server itself but rather a problem with the information the server has been instructed to access or return as a result of the request. This error is often caused by an issue on your site which may require additional review by support teams.
Please, contact your host provider.
Feature List not included in Language Manager of Joomla Real Estate Component, you can add any Feature in any language, and then assign them on house you need. You can create any new category in any language. So, this is much better than include them in Language Manager.
You need only add Amenities (Garden, Yard, Heating, etc.) in German or English, for example, just write them in that languages in Real Estate Manager : Amenities Manager.