Random range on dynamic color assign Fail

#1

Hello.
I have 3 particle systme that run in this way.
1: nParticleShape1.rgbPP=<<rand(1),rand(1),rand(1)>>;
2 emitted from the 1:
vector $color =particle -at rgbPP -id (nParticleShape2.parentId) -q nParticle1;
nParticleShape2.rgbPP=$color;
I’ve added on 2 parentID
2: emitted from the 2 particles system:
vector $color =particle -at rgbPP -id (particleShape1.parentId) -q nParticle1;
particleShape1.rgbPP=$color;
All run well without this expression, but when i’m started to add this expression, maya returns an error:
maya rgb color Error: line 0: Could not find particle with id specified. Please check id value in the query command //// Error: An execution error occurred in the creation expression for particleShape1. //
All run if i made the lifespan mode to live forever. but when i change to ranomd or constant I get this erro.
If anyone have an Idea. I’m running in a problem big because I’m not great with expression, so I cannot advance anymore.
Thanks