If your game crashes to desktop and displays an "Out of reserved memory" error, you should try one or both of the following:

1) Run the application FlashpointPreferences.exe (located in your game's directory, C:\Program Files\GOG.com\Operation Flashpoint GOTY\ by default) and click the Autodetect button,

2) Add two command line parameters to the game's shortcut. To do so, right-click on the shortcut and select Properties. In the "Target:" field, after the ending quotation mark, make a space and type in -nosplash -nomap>.

Alternatively, you could try using the Enhanced Configuration Project mod, as its developers could have fixed this memory leak issue.