Render log returns this using a basic scene containing a cube only - presumably the last line is the most important:
Detecting available GPU(s)...
Device number: 0
Name: Quadro 4000
Memory: 2014 MB
Type: OpenCL
Scene file path: 'C:\Users\adown\AppData\Roaming/Indigo Renderer/default.igs'
Sky zenith luminance: 3387.095215 cdm^-2
Rendering with GPU acceleration
Forcing bidirectional=false, hybrid=false, batched=true
Light luminous flux (geometry name=EnvSphereGeometry): 5.746E+009 lm
Building Object Tree...
1 objects.
calcing root AABB.
AABB: (0.236831, 0.292659, 0.000000), (3.618678, 5.213458, 2.038000)
max tree depth: 2
reserving N nodes: 1(8 B)
total nodes used: 1 (8 B)
total leafgeom size: 1 (8 B)
Finished building tree.
AutoFocus: setting camera focus distance to 5.76820 m.
Num buffer layers: 1
Master buffer size: 20.960 MB
Auxiliary buffer size: 48.307 MB
Settings:
Image width: 958 px
Image height: 466 px
Internal image width: 1932 px
Internal image height: 948 px
Verbose: false
Display period: 10.00000 s
Image save period: 60.00000 s
Frame upload period: 40.00000 s
Splat filter: FastBox
Downsize filter: mn_cubic, blur=0.33330, ring=0.33330, support=4.00000px
Render region: false
Supersample factor: 2
Metropolis: false
Bidirectional: false
Hybrid: false
Aperture diffraction: false
Post-process diffraction: true
Auto setting number of threads to 8.
Finished initialisation (Time Taken: 0.07843 s)
Time to render thread start: 0.07898 s.
Starting threads... (num threads:

OpenCL build log: :5: error: ilegal address space on image or sampler type
__constant sampler_t l1lll11l1l1 = CLK_NORMALIZED_COORDS_FALSE | CLK_ADDRESS_CLAMP_TO_EDGE | CLK_FILTER_NEAREST; inline float4 ll1l1l11lll(read_only image2d_t texture, const uint ll1l1lllll1) { const uint y = ll1l1lllll1 / OMTX; const uint x = ll1l1lllll1 % OMTX; return read_imagef(texture, l1lll11l1l1, (int2)(x, y)); }
Error initialising GPU ray tracer: Build failed
Not sure what that means...