My search string was FF FF 00 01 00 for the game v1.1.36. 1. Unpack your save zip (on my PC it is located in c:\Users\keht\AppData\Roaming\Factorio\saves\). Make sure you have a backup! 2. Find a lot of 'level.datX' files 3. Starting from the last file do: - Using the tool provided by pawelzwronek (...