JManderley: So as of this post, May 1st 2020, the Quicksave function does _not_ work, it just flashes up a message very briefly but writes nothing to the save game folder. Quickload will load back in the _autosave_, which is basically a checkpoint save made after the successful completion of a mission.
If this was the original intent of this feature then one must ask why it was included in the first place, surely the purpose of a Quicksave feature is to save the game at the exact point of the game the player is currently at, including progress, and enables the player to Quickload back to that exact point should something go horribly wrong with their gameplay.
In this case, when quicksave is used _no_ file is written to the savegame folder, therefore one can only assume that it does _not_ work as intended.
One can also assume that this will never be fixed officially due to the fact that the software company went bust at the time of the game release...
Sorry, unless somebody wants to patch this then the GOG version of this game will never have a working quicksave :(
The game still won't save, not mission, not after completing the mission, it just won't save. The saves in the menu read "Last completed mission: No mission". I'm uninstalling.