Right click on the shortcut and select 'Open file location', then run the game from the SupportTool.exe file, rather than EoCApp.exe.

If you click on Campaign, then Load Game, can you select individual saves to load?

If you select Profiles on the main menu and create a new profile, can you start a new game and save / load, exit to the main menu and continue?

Are you shutting down all non-essential programs (especially anti-virus) before starting the game? Firewalls can also cause conflicts, generally on startup or loading screens.