I too am having this issue, and it has effectively broken the game for me. I can travel back so far to an Autosave but it crashes before it gets back to the Geoscape. I believe this was my 15th crash landing, with 1 terror mission behind me. If it proves useful I can provide all my save games as well up to this point... I had 6 manual saves, as well as the 3 autosaves.