Up until very recently the Steam Cloud function has never had any issues for me. However, upon creating a new world and putting it on the cloud, the game gives the "Load Failed! No Backup Found" error and moves the world file directly into the recycling bin. Creating and putting new characters on the cloud works fine, and worlds not on the cloud work as normal. Every other instance of this problem I could find was caused by people using mods and still I couldn't find any solution. I've used...
"Load Failed! No Backup Found" Error for Worlds on Steam Cloud
"Load Failed! No Backup Found" Error for Worlds on Steam Cloud