You added a texture that is too large (e.g., 2048x2048 when the engine expects 256x256). Fix: Use Magic.TXD to compress the texture. For GTA3, do not exceed 512x512 for most objects. 1024x1024 for skies only.
But his crown jewel was the folder labeled GTA3_IMG_EXTRA_QUALITY . gta3 img file extra quality