same thing here and the devs dont even respond via e-mail or their own damn forums.
This bug has been submiited several times and no official response yet.
Some one has found the possible cause and also a solution.
It fixed my .sav and many others.
Check here for the source code and the excutable .exe
(Sorry I don't have permission to post links, add the line below after the reddit address)
/r/foshelter/comments/3ibmnt/objectives_crashing_and_possible_cause/
Do a search here in the forums for the exact same title you used and you will find the solution, as mentioned above.