you use the linux version, so yes this is not my fault this the FNA lib bug, but they correct it, so i will fix it ;). Thanks for much. I didn't "use" SDL i use FNA this is an reimplemention of xna, but the creator of fna have code a binding of sdl for c# and he use it in FNA, this is https://fna-xna.github.io/ FNA link. It's a full code oriented game lib.