I am using the Draftsight beta version on MacBook Pro since early 2015. I am now using the version 2016 SP2. The problem is that the error of memory shortage appears very frequently and freeze my computer. But I can hardly believe the memory shortage, because my computer has 16GB (1867 MHz DDR3) of memories and it should be quite sufficient. I haven't met the similar problem with my previous MacBook Pro 2013. It looks very much like software's memory allocation bugs or some kind of hardware problems for me. It is helpful if any of you may know any known problem with software or hardware.