Visualization, TKOpenGl - Weighted OIT + MSAA shader compilation errors

        #version 300 es
      <...>
      uniform sampler2DMS uAccumTexture;
      uniform sampler2DMS uWeightTexture;
      THE_SHADER_IN vec2 TexCoord;
      void main()
      {
        ivec2 aTexel  = ivec2 (textureSize (uAccumTexture) * TexCoord);
        vec4 aAccum   = texelFetch (uAccumTexture,  aTexel, gl_SampleID);
        float aWeight = texelFetch (uWeightTexture, aTexel, gl_SampleID).r;
        occSetFragColor (vec4 (aAccum.rgb / max (aWeight, 0.00001), aAccum.a));
      }
21:50 TKOpenGl | Type: Error | ID: 0 | Severity: High | Message:
        Failed to compile shader object. Compilation log:
      ERROR: 0:268: '*' :  wrong operand types  no operation '*' exists that takes a left-hand operand of type '2-component vector of int' and a right operand of type 'varying 2-component vector of float' (or there is no acceptable conversion)
      ERROR: 0:269: 'gl_SampleID' : requires extension GL_OES_sample_variables to be enabled 
      ERROR: 0:270: 'gl_SampleID' : requires extension GL_OES_sample_variables to be enabled 
      ERROR: 3 compilation errors.  No code generated.
21:50 TKOpenGl | Type: Error | ID: 0 | Severity: High | Message:
        Initialization of OIT compositing pass has failed.
        Blended order-independent transparency will not be available.
21:50 TKOpenGl | Type: Error | ID: 0 | Severity: High | Message:
        Initialization of OIT compositing pass has failed.
        Blended order-independent transparency will not be available.

21:49 EGLVersion: 1.4 Android META-EGL
      EGLVendor: Android
      EGLClientAPIs: OpenGL_ES
      GLvendor: Qualcomm
      GLdevice: Adreno (TM) 530
      GLversion: OpenGL ES 3.2 V@145.0 (GIT@I25dc76dc3f) [GLSL: OpenGL ES GLSL ES 3.20]
      Max texture size: 16384
      Max combined texture units: 96
      Max MSAA samples: 4
      Viewport: 2048x1488
      Display scale: 1.7