I've checked your site.

 

After I click the save button, I got the following error:

 

Value cannot be null. Parameter name: path
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.ArgumentNullException: Value cannot be null. Parameter name: path

 

Editor1.SaveFile(template);
Line 50:    Response.Redirect("/admin/default.aspx?VisitorID=" + VisitorID + "&MenuItemID=" + MenuItemID + "&MenuID=" + MenuID);

It looks like you the Parameter for Editor.SaveFile method is not correct.

 

Keep me posted