Matrix parameter not recognised in pixel shader?

Graphics
2

How are you setting the Projection value from C#? That would be my best guess as to where the problem lies, as I’m setting my Projection as a matrix in pretty much all my shaders and not seeing this particular issue.

Shader snippet:

matrix Projection;
VSOutput VSQuad(VSInput input)
{
	VSOutput output;

	float4 worldPosition = mul(input.position, World);
	float4 viewPosition = mul(worldPosition, View);
	output.position = mul(viewPosition, Projection);

	// Lots of unrelated code

	return output;
}

And in code when setting:

UnitRenderEffect.Parameters["Projection"].SetValue( projMat );

Where projMat is a Matrix object and UnitRenderEffect is an Effect object.

I did a quick sanity check and changed my Projection variable in the shader from matrix to float4x4 but it still worked so I don’t think there is an issue there.