Game client crash rate increasing exponentially for no apparent reason?

[SquarianSquare]

1. What do you want to achieve? Keep it simple and clear!
   My game (Truck Chaos)'s crash rate has increased exponentially, from barely 2% to almost 50% today. I want to figure out the reason, since I have not changed the code or added more features that could have affected performance.

2. What solutions have you tried so far?

I have published multiple updates which use optimization techniques from the documentation, but to no avail, even though my stats (memory wise) seem good.