We have been investigating this problem and for many players issue got fixed if they made sure they were online on Steam.
We recommend restarting the game and reloading the world after making sure you are online on Steam. You have tried this, but the crane is still not working? Send us a report here and we will help you out as soon as we can! Also, make sure to attach the problematic save file to the report!
You can find your save files here:
C:\Users\USERNAME\AppData\LocalLow\Redbeet Interactive\Raft\User\User_xxxxxxxxxxxxxxxxx\World\SaveName\SaveName-Latest