Thought I would post this incase people missed it. This link is for the specific 55x8509C but am sure it states it is relevant for all 2015 and 2016 Android TV's
http://www.sony.co.uk/support/en/content/cnt-hn/prd-tvhc/Opera-TV-Store-Service/KD-55X8509C Contents of the site - Dear Valued Sony Customer, Sony notifies Customers of the discontinuance of distributing the Opera TV Store service (ver. 1.0) on Sony’s 2015 and 2016 Android TVs due to the expiration of the contract regarding this service between Sony and Opera TV AS. The Opera TV Store app will be removed from these TVs and the feature will not be accessible after 15th March 2017.* We thank you for your understanding and apologise for any inconvenience this may cause. * NOTE: This app closure does not affect the Opera Browser.