ERROR: error(#277) Symbol 'pos[0]' usage doesn't match between two stages

varying in vec3 pos[4];
varying out vec3 position;
varying out vec3 normal;

void main() {
   vec3 Normal = ((pos[3] - pos[1]) * (pos[3] - pos[2])).xyz;
   /*for (int i1 = 0; i1 < 4; ++i1) {
      position = pos[i1];
      normal = Normal;
      gl_Position = gl_PositionIn[i1];
      EmitVertex();
   }*/  // ursprünglich benutzte ich diese Schleife. Hab dann probiert, ob die den Fehler verursacht, lag aber falsch

   position = pos[0];
   normal = Normal;
   gl_Position = gl_PositionIn[0];
   EmitVertex();

   position = pos[1];
   normal = Normal;
   gl_Position = gl_PositionIn[1];
   EmitVertex();

   position = pos[2];
   normal = Normal;
   gl_Position = gl_PositionIn[2];
   EmitVertex();

   position = pos[3];
   normal = Normal;
   gl_Position = gl_PositionIn[3];
   EmitVertex();
}

  glProgramParameteriEXT(FProgram, GL_GEOMETRY_VERTICES_OUT_EXT, 4);
  glProgramParameteriEXT(FProgram, GL_GEOMETRY_INPUT_TYPE_EXT, GL_Quads);
  glProgramParameteriEXT(FProgram, GL_GEOMETRY_OUTPUT_TYPE_EXT, GL_Quad_STRIP);

varying in vec3 pos[3];
varying out vec3 position;
varying out vec3 normal;

void main() {
   vec3 Normal = ((pos[0] - pos[1]) * (pos[0] - pos[2])).xyz;
   /*for (int i1 = 0; i1 < 3; ++i1) {
      position = pos[i1];
      normal = Normal;
      gl_Position = gl_PositionIn[i1];
      EmitVertex();
   }*/

   position = pos[0];
   normal = Normal;
   gl_Position = gl_PositionIn[0];
   EmitVertex();

   position = pos[1];
   normal = Normal;
   gl_Position = gl_PositionIn[1];
   EmitVertex();

   position = pos[2];
   normal = Normal;
   gl_Position = gl_PositionIn[2];
   EmitVertex();   
}

#extension GL_EXT_geometry_shader4: enable

uniform int time;
varying vec3 pos;

void main() {
  vec4 Vertex = gl_Vertex;

  // da kommt die Funktion rein
 
  gl_Position = gl_ModelViewProjectionMatrix * Vertex;
  gl_FrontColor = gl_Color;
  pos = vec3(gl_ModelViewMatrix * Vertex);
}

#extension GL_EXT_geometry_shader4: enable

varying in vec3 pos[3];
varying out vec3 position;
varying out vec3 normal;

void main() {
   vec3 Normal = ((pos[0] - pos[1]) * (pos[0] - pos[2])).xyz;
   for (int i1 = 0; i1 < 3; ++i1) {
      position = pos[i1];
      normal = Normal;
      gl_Position = gl_PositionIn[i1];
      EmitVertex();
   }   
}

uniform sampler2D Texture0;
uniform int ActiveLights;
 
varying vec3 position;
varying vec3 normal;
 
void main(void)
{
  vec3 lightDir;
  float  attenFactor;
  vec3 eyeDir          = normalize(-position); // camera is at (0,0,0) in ModelView space
  vec4 lightAmbientDiffuse    = vec4(0.0,0.0,0.0,0.0);
  vec4 lightSpecular       = vec4(0.0,0.0,0.0,0.0);    
 
  // iterate all lights
  for (int i=0; i<ActiveLights; ++i)
  {
   // attenuation and light direction
   if (gl_LightSource[i].position.w != 0.0)
   {
      // positional light source
      float dist   = distance(gl_LightSource[i].position.xyz, position);
      attenFactor   = 1.0/(   gl_LightSource[i].constantAttenuation +
               gl_LightSource[i].linearAttenuation * dist +
               gl_LightSource[i].quadraticAttenuation * dist * dist );
      lightDir   = normalize(gl_LightSource[i].position.xyz - position);
   }      
   else
   {         
      // directional light source         
      attenFactor   = 1.0;         
      lightDir   = gl_LightSource[i].position.xyz;      
   }       
   // ambient + diffuse      
   lightAmbientDiffuse    += gl_FrontLightProduct[i].ambient*attenFactor;      
   lightAmbientDiffuse    += gl_FrontLightProduct[i].diffuse * max(dot(normal, lightDir), 0.0) * attenFactor;
   // specular      
   vec3 r       = normalize(reflect(-lightDir, normal));
   lightSpecular    += gl_FrontLightProduct[i].specular *
               pow(max(dot(r, eyeDir), 0.0), gl_FrontMaterial.shininess) *
               attenFactor;   
  }    
  // compute final color   
  vec4 texColor = gl_Color;// * texture2D(Texture0, gl_TexCoord[0].xy);   
  gl_FragColor    = texColor * (gl_FrontLightModelProduct.sceneColor + lightAmbientDiffuse) + lightSpecular;
 
  float fog   = (gl_Fog.end - gl_FogFragCoord) * gl_Fog.scale;   // Intensität berechnen
  fog      = clamp(fog, 0.0, 1.0);              // Beschneiden
  gl_FragColor    = mix(gl_Fog.color, gl_FragColor, fog);        // Nebelfarbe einmischen
}