ContextCapture FAILED: failed to init rasteriser

I have successfully produced a 3D mesh and can produce a tiled orthophoto/DSM, but I cannot produce an untiled, continuous orthophoto. It seems that every time I try to produce a figure with a maximum image part dimension greater than 20000 pixels I get a 'FAILED: failed to init rasteriser' error. Is there something that I am missing/doing wrong, or is there a fixed limit to the maximum image part dimension and if so what is it?

  Production_6 - Part_1_1.zip