Particle Effects - "You do not have the correct version..." Error

hi,

i tried to integrate a simple smoke effect into my game, but theres always the same result. the effect appears for about half a second, then the game stops and shows the following error message:

"You do not have the correct version of the 3D Cilent or the related art needed to enter this world. (invalid packet (failed to register ghost))."

the console shows this:

"Could not register base emitter for particle of class: FireParticleEmitterNode"

i am usinger version 1.8.1 and the art is definitely in the right folder. so where could be the problem?
here is my campFireFx.cs source file:



datablock ParticleData( FireParticle )
{
textureName = "~/data_icura/shapes/campfire_particles/fire";
dragCoefficient = 0.0;
gravityCoefficient = -0.3; // Gravity pulls down, but a negative value makes the particles rise instead of sink
inheritedVelFactor = 0.00;
useInvAlpha = false;
spinRandomMin = -30.0;
spinRandomMax = 30.0;

lifetimeMS = 500;
lifetimeVarianceMS = 250;

times[0] = 0.0;
times[1] = 0.5;
times[2] = 1.0;

colors[0] = "0.8 0.6 0.0 0.1";
colors[1] = "0.8 0.6 0.0 0.1";
colors[2] = "0.0 0.0 0.0 0.0";

sizes[0] = 1.0;
sizes[1] = 1.0;
sizes[2] = 5.0;
};

datablock ParticleEmitterData( FireParticleEmitter )
{
particles = "FireParticle";

ejectionPeriodMS = 15;
periodVarianceMS = 5;

ejectionVelocity = 0.25;
velocityVariance = 0.10;

thetaMin = 0.0;
thetaMax = 90.0;
};

datablock ParticleEmitterNodeData( FireParticleEmitterNode )
{
timeMultiple = 1;
};

//-----------------------------------------------------------------------------
// Where there's fire... there's smoke, so the second thing we need to do is
// create a second particle system to represent the smoke.
//
// SmokeParticle - Defines how individual particles behave.
// SmokeParticleEmitter - Defines how the particles enter the world.
// SmokeParticleEmitterNode - The particle system's node for world placement.
//-----------------------------------------------------------------------------
datablock ParticleData( SmokeParticle )
{
textureName = "~/data_icura/shapes/campfire_particles/smoke";
dragCoefficient = 0.0;
gravityCoefficient = -0.2; // Gravity pulls down, but a negative value makes the particles rise instead of sink
inheritedVelFactor = 0.00;
useInvAlpha = false;
spinRandomMin = -30.0;
spinRandomMax = 30.0;

lifetimeMS = 3000;
lifetimeVarianceMS = 250;

times[0] = 0.0;
times[1] = 0.5;
times[2] = 1.0;

colors[0] = "0.6 0.6 0.6 0.1";
colors[1] = "0.6 0.6 0.6 0.1";
colors[2] = "0.6 0.6 0.6 0.0";

sizes[0] = 0.5;
sizes[1] = 0.75;
sizes[2] = 1.5;
};

datablock ParticleEmitterData( SmokeParticleEmitter )
{
particles = SmokeParticle;

ejectionPeriodMS = 20;
periodVarianceMS = 5;

ejectionVelocity = 0.25;
velocityVariance = 0.10;

thetaMin = 0.0;
thetaMax = 90.0;
};

datablock ParticleEmitterNodeData( SmokeParticleEmitterNode )
{
timeMultiple = 1;
};