Call of Duty: Modern Warfare 2 has a very detailed weapon attachment system that includes different mechanics throughout the game. Players are able to level up their weapons and unlock a wide variety of attachments for them. In the end, when a weapon is leveled up to the maximum rank, this unlocks the ultimate ability of “attachment tuning” for the related weapon.
This ability allows players to finetune their use of attachments, as the game provides sliders for certain stats in the attachments. Unfortunately, this system was found to be causing crashes and it was recently disabled. According to the claims, when a player attempts to tune all five attachments on the weapon, it used to cause crashes. Infinity Ward acknowledged the problem and a fix was in progress.
After some work, developers finally fixed the feature and re-enabled it so players can enjoy loadouts fully adjusted for their own playstyle and performance. This is far from being the only issue though, as Nvidia drivers had some problems recently and a previous fix was needed for in-game ping system.