Monsters like Cobra and Minotaur Archer have a sprite of 32x32 pixels when idle, but when they are moving they have 64x64 sprites. OTClient (and RME) don't understand that and crash when the monster goes on screen.
One solution: open Tibia.spr (or Tibia.dat) with an object builder and change all sprites from these monsters to 64x64.
Monsters like Cobra and Minotaur Archer have a sprite of 32x32 pixels when idle, but when they are moving they have 64x64 sprites. OTClient (and RME) don't understand that and crash when the monster goes on screen.
One solution: open Tibia.spr (or Tibia.dat) with an object builder and change all sprites from these monsters to 64x64.