How do I increase the max Shader Samplers?/Decrease the amount it's using?

I recently changed my terrain textures from the preset ue4 ones to 2K Quixel textures, after doing this though I have suddenly run across this issue and I can’t seem to fix it, originally I thought it was because the textures were 4K but even downgrading to 2K hasn’t solved it, can anyone please help me?