If the problem was universal then it would be happening to every single one of us, every time, so Game Engine is not only at play here.
Generally games crash because;
They run out of memory, when the game has to deal with moving an object that doesn't exist, this is something unexpected and so it breaks, allowing programs to crash was a deliberate design by choice made way back when memory was a major limiting factor; and it's stayed with us since.
Get interrupted while saving and the game files gets corrupted .
Get interrupted by another program or overheat.
Video Card Drivers can play a big role of crashing.
Anti-Virus can cause problems as well.
Hardware-related crashes, Although crashes caused by hardware are possible, most computer crashes are caused by errors in the OS software
Glitches, sometimes (although not that rarely) a component in your computer can experience transitory glitches
HDD/SSD
Software-related crashes
bugs in device drivers
And so on.
Trainers typically sit in RAM and observe the kind of instructions a game-exe file is sending and receiving
For e.g., it might come across a message in the game that says "Player hit by enemy. -10 Health points for damage." This message would then be read by the game to adjust the "player file" to lower the health point by 10 points.
The trainer will intercept this message and instead change it to "Player hit by enemy. 0 health points for damage." So the game will not change the health points stored in the "player file". This is essentially how god mode works.
Sometimes though, the trainer might send an instruction that is in a format that can't be recognised by the game file.
Because the game-exe file is not able to understand the message, it throws out an error which leads to a game crash.
and sometimes, just activating trainers without actually using any tricks crashes the game on some PCs while the entire thing works fine on some others.
there is a lot at play when it comes to crashing, the game code is spaghetti there's no denying that.. but.. it's not solely on Game Engine, your computer comes at play as well.
They tell you this, because it's the easiest way to fix most of the problems caused by corruption in files, sure you can go on about and manually figuring it out and fixing it yourself, but it won't be as fast or as simple as Re-installing. However if the problem that you are having is not related to the gaming files but rather something else, then even Re-installing the game will not fix the problem, that's why you have "Event Viewer" and that's where you should always go when investigating where the problem lays.
One of the most common causes of a slow download rate is a poor internet connection. What you need to understand is that your download speed is affected by the entire connection chain. You are not connecting your PC directly to a NCSOFT datacenter; it rather looks like this:
[Your PC] ← → [Your internet provider’s local hub] ← → [Your internet provider’s Tier 1 connection] ← → {optional: International routing} ← → [NCSOFT content server]
Your ISP may have some bottlenecks on connections to different locations, sure NCSOFT Servers play a role in how fast you download as well, But so does your internet and your data can take a multitude of different routes between your computer and a remote server. Sometimes transfers simply get caught up in congestion along the way. Further, traffic from different ISPs (or even different locations with the same ISP) will be routed differently