A number of people have run into a weird issue where they aren't able to save/restor after installing Episode 4. The game doesn't crash, it just doesn't actually seem to be creating the save files. There are two suggestions I have to resolve this:
1. Run the game as an administrator. This seems to have about a 50/50 chance of working from what I've seen. To do this, go into the folder where the game is installed on your computer, right-click the TSL.exe icon, go into the Properties option, then on the Compatibility tab click the checkbox to run the program as an administrator.
2. Reinstall the game in a directory other than Program Files. Uninstall The Silver Lining and then just run the full installer for Episodes 1-4 again and when it asks for an installation directory just put C:\TSL or really pretty much anything that doesn't use Program Files or Windows as the directory.