Strange 'ERROR: Primitive' message

Hi,

I have just came back to some supercollider code i was using yesterday with no problems, however I am now getting this error

ERROR: Primitive ‘_Event_Delta’ failed.
Wrong type.

Here is the code

(
SynthDef(\Grain,
	{var sig, grain, env, sum, filt, pan1,pan2;
		sig = DynKlank.ar(`[Array.fill(14,{Rand(\freqlow.kr(100),\freqhi.kr(20000))}),Array.fill(14,{ExpRand(0.128, 0.7)}),Array.fill(14,{ExpRand(0.5, 0.9)})],BrownNoise.ar(0.7));
		grain = GrainIn.ar(1,Dust.kr(14), 0.0128, sig);
		grain = CombC.ar(grain, LFNoise0.kr(0.7).range(0.7,3),0.7, 7);
		env = EnvGen.kr(Env.sine(TRand.kr(1.28,3, Dust.kr(0.07))), Dust.kr(\size.kr(20)),
		doneAction: 2
		);
		filt = LPF.ar(sig, \cut.kr(1000));
		sum = filt*env;
		pan1 = Pan4.ar(sum, FSinOsc.kr(0.128,(pi * 1)), FSinOsc.kr(0.128,(pi * 0.5)));
		pan2 = Pan4.ar(grain, FSinOsc.kr(0.07,(pi * 2)), FSinOsc.kr(0.07,(pi * 1.5)));
		Out.ar(0, pan1+pan2*\amp.kr(0.01));
}).add;
)
\freqlow.kr(100)

/


(
Pbind(\instrument, \Grain,
	\dur, Rand(3.0, 12.0),
	\cut, 3000,
	\amp, 0.0002,
	\size, 0.2,
	\freqlow, 300,
	\freqhi, 12000,
).play;
)

Is anyone able to test this to see if they have the same issue? And if so any ideas what this error means?

Rand is a server UGen, not a pattern.

\dur, Pwhite(3.0, 12.0, inf)

hjh