Not sure if there was an update to bdsup2sub++ that causes it to consume almost all memory which causes all applications to be killed or it almost consumes all memory and it does eventually complete, but the subfile is has a zero size. I'm burning in subtitles for my mobile versions.
Is it still necessary to convert sup to sub to burn in the subtitles. I've had issues with color conversion between the two when burning 10bit color.