Rendering Resolution Disabled??

[DavidVC]

Hello, i get a new graphic card, and want to get more graphics on the ppsspp, but... i see the rendering resolution are in grey, like disabled... I dont know its like that, i saw a tutorial to improve graphics, but in the tutorial are enable.

Why its happen this?. I try to change in the options some stuff to see if i can enable it, but nothing works.

Can someone help me?.

P.D.: Im still want to search another better tutorial to get more graphics, so if know other, please tell me.