Update 1.0.14+ make the old saves invalid. In order to upload the save of the previous version, you need to switch back to the previous version of the game. How to do it:
1) Open Steam.
2) Go to the Library
3) Click right mouse button on the name of the game, choose Properties;
4) Go the "BETA" tub
5) Choose the version you need
6) Close the Properties window. Game should automatically switch to the version you selected.
When you will finish the game, you can go back to the latest version, just choose the default version in the same "BETA" menu.