WHAT IS THE CLASS OF '09 DIVERGENT BUILD PHENOMENON? [EXTENDED]

The Divergent Class of '09 Copies phenomenon is a strange digital oddity involving pirated copies of Class of '09 uploaded onto torrenting sites, most notably The Pirate Bay. These uploads began appearing sometime after the release of the second game, usually under misleading titles such as Class of '09 Remastered or Class of '09: The Double Up Collection. No known upload has ever remained available for long, and no two recovered copies have ever been completely identical.
At first glance, most divergent copies appear to simply be low quality repacks or slightly modded in some way, commonly reported irregularities include slightly altered title screen music, pre-existing save data, inconsistent audio mixing, or missing credits information
more unstable builds have been reported to contain severe abnormalities such as entirely absent voice acting, inaccessible endings, route specific crashes, corrupted save thumbnails, and dialogue that references events impossible to encounter in a normal playthrough

An example of a unstable build lacking the "girl hormones make me feel guilty" choice that leads to the nicole suicide ending
this build is known as the mute build due to its lack of audio, more info on documentation

The phenomenon becomes especially concerning due to the inconsistencies between recovered copies. Some users report routes completely absent from their installations, while other describe scenes and interactions that do not exist in retail versions of the game
One recurring detail accross nearly all documented divergent copies is Nicole's behavior. While the game initially appears structurally similar to the retail release, Nicole herself is often described as subtly wrong, Her expressions may fail to change properly during conversations, emotional scenes may play out with completely neutral sprites, and in some cases she appears to recognize characters or events long before she logically should. Later routes within affected copies frequently contain continuity errors involving previous endings, including references to deaths, conversations, or choices from entirely different routes.

An example of Nicole not showing the correct sprite during part of the moving away ending route, note that the dialog slightly differs of that from the retail version

Several users documenting the phenomenon have also reported progressive instability over extended play sessions. Builds may begin crashing more frequently after route completion, menus may stop functioning correctly, and previously accessible scenes may disappear entirely between launches. Some archived copies eventually become unbootable altogether, displaying generic operating system errors such as “This app can’t run on your PC.” Attempts to reverse engineer affected builds have reportedly produced inconsistent results, with certain copies containing unusually encrypted or malformed data structures not present in retail versions of the game.

Evidence of what's known as "Build Decay", after enough launches, the game stops booting up