More information HERE.
To all Samsung TV owners, kindly disconnect your TV/SmartTV from the internet while Samsung (attempts to) fix a broken firmware update released in the last 48 hours (25 August 2017).
Hope this helps.
NOTE: The first users who reported the issues were the Europeans and then followed by the Americans. So it is yet "unknown" if this broken update will affect any Australian users but I think it's best to throw caution in the air.
Samsung TV owners furious after software update leaves sets unusable
Ha, so much for a "Smart" TV.