Hi,
I am trying to add a Logo image field to SiteCOnfig under SS 3.1. I first followed the instructions on extending SiteConfig at http://doc.silverstripe.org/framework/en/reference/siteconfig : everything went Ok.
I then changed the lines

private static $db = array(
   'FooterContent' => 'HTMLText'
   ); 
public function updateCMSFields(FieldList $fields) {
  $fields->addFieldToTab("Root.Main", new HTMLEditorField("FooterContent", "Footer Content"));
}

private static $has_one = array(
  'LogoImage' => 'Image',		
  );
public function updateCMSFields(FieldList $fields) {
  $fields->addFieldToTab(
    "Root.Main", new UploadField("LogoImage", "Choose an image for your site logo"));
}

but it doesn't work. I can select a file for download (no drag and drop area however), but on validating, the screen is not updated to reflect my choice, and while, on saving, a message tells me "saving is Ok, nothing at all is uploaded.

This worked perfectly in SS 3.05.
Thanks for help

After upgrade to SS 3.1.1, problem still pending ...
Any idea ?

Curious, I have Image realtions on SiteConfig extension working fine on a few sites. The fact that field is rendering correctly may be the problem

Just tested your code on a complete fresh copy of the latest stable version (3.1.2), seems to all work perfectly.

Make sure you have run a dev/build (either in the browser http://localhost/dev/build/ or via command line) to ensure the database actually has the column in the DB to save the Image relationship.

I would like to point to this post.

http://www.silverstripe.org/customising-the-cms/show/21490

I don't know if it has anything to do with your problem, but there seems to be a (FireFox) issue with 'UploadField -> from your computer' after a CMS reload...

Martine