This issue is likely due to an incompatibility with the current version of the game. If you previously had a mod installed, you will need an updated version of that mod to access your save file. If not, it is likely due to an anomaly with PC part data. Try to remember which parts you had in the save file before it broke before you submit a support ticket.
If you play on PC, you can send us your unmodded save file and PC part info.
If you play on console send your PC Part info.