It could also be due to the parameters in your FX file. If you have set the particle rate wrong, then the light loses its intensity and it finally goes out completely. It would be an advantage if we could see the contents of the FX file to see if the parameters are in good range..
Hi
Attach the FX file I made, thank you.
[Library Effect]
Lifetime=5
Version=2.00
Radius=-1
Priority=0
[Properties]
Spot=1
Tower=1
Map=1
[Emitter.0]
Lifetime=0.50, 0.50
Delay=0.00, 0.00
Bounce=0.00
Rate=1.00, 1.00
X Emitter Velocity=0.00, 0.00
Y Emitter Velocity=0.00, 0.00
Z Emitter Velocity=0.00, 0.00
Drag=0.00, 0.00
X Particle Velocity=0.00, 0.00
Y Particle Velocity=0.00, 0.00
Z Particle Velocity=0.00, 0.00
X Rotation=0.00, 0.00
Y Rotation=0.00, 0.00
Z Rotation=0.00, 0.00
X Offset=0.00, 0.00
Y Offset=0.00, 0.00
Z Offset=0.00, 0.00
Pitch=0.00, 0.00
Bank=0.00, 0.00
Heading=0.00, 0.00
[Particle.0]
Lifetime=0.000000, 0.000000
Type=28
X Scale=250.00, 250.00
Y Scale=0.00, 0.00
Z Scale=0.00, 0.00
X Scale Rate=0.00, 0.00
Y Scale Rate=0.00, 0.00
Z Scale Rate=0.00, 0.00
Drag=0.00, 0.00
Color Rate=0.00, 0.00
X Offset=0.00, 0.00
Y Offset=0.00, 0.00
Z Offset=0.00, 0.00
Fade In=0.00, 0.00
Fade Out=0.00, 0.00
Static=1
Face=0, 0, 0
[ParticleAttributes.0]
Color Start=255, 224, 192, 0
Color End=255, 224, 192, 110
Bounce=0.00
X Scale Goal=0.00
Y Scale Goal=0.00
Z Scale Goal=0.00
Falloff Exponent=2.00
Inner Cone Angle=1.00
Outer Cone Angle=51.00