Vertex Attribute error in Shader

Hi all,
I get this error in the console:

jit.gl.shader: GLSL attribute name not valid: 'sizeAttr'

when declaring a VERTEX_ATTR in my shader with the following code.
I have done this already other times and it was working, now suddenly doesn't work in this code. Can you spot the error?
I tried also an empty shader and just declaring the vertex attribute gives the error.

This is the jit.gl.mesh to which the shader is attached:

jit.gl.mesh game @draw_mode points @color 0.7 0.7 0. 7 0.7 @shader shady1 @texture particleTex @blend_enable 1 @depth_enable 0 @blend alphaadd

Thank you for any help!

<jittershader name="Particles">
    <param name="tex0"        type="int" default="0" />
    <param name="size"        type="float" default="0.015" />
    <param name="sizeAttr"    type="float" state="VERTEX_ATTR" />
    <param name="view_matrix" type="mat4"  state="VIEW_MATRIX" transform="INVERSE_TRANSPOSE"/>
    <language name="glsl" version="1.2">
        <bind param="tex0" program="fp" />
        <bind param="sizeAttr" program="vp" />
        <bind param="view_matrix" program="gp" />
        <bind param="size" program="gp" />
 

        <program name="vp" type="vertex">
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