Can you load the old version to the new version?
if you use windows then download the new version, go to C:\Users\<USERNAME>\AppData\LocalLow\Denki\Autonauts amd take take <your world's name>.txt and put it in the Autonauts file, under the app and not in the data.
if you use macOS then you will need to right click (or press with 2 fingers on the trackpad) on the old version, select the second option (Show Package Contents) and then select <your world's name>.txt
put that in a place that you would be able to find it, download the new version, right click on it, select the second option and put <your world's name>.txt BELOW the file called contents, NOT in it.
if you use linux, well, i don't know.