Since 688i doesn't have a dedicated forum yet, most players will encounter a problem; the game will run, but there are no sound effects. This is due to the antiquated compression format that the sound effects are packed in within the game files. Modern Windows operating systems can no longer read them directly, resulting in the problem.

SOLUTION: The program SCSoundEdit is a decompressor that is specifically made to handle the .agg sound compression in the game files. The utility when run will decompress the sound files in the archive so that the game can implement them without resorting to the archive. When the sound effect files (all .WAV format) are extracted, the game runs normally.

Currently, the decompressor is available at Subsim.com, where it has been available for several years. Below is the link:

Sub Command SoundEdit Utility

When 688i gets its own dedicated forum, I will repost this thread to help players that encounter this issue, which should be almost everyone with a modern OS (Win 7+)