I use SU 2017 as a subscription doesn't make sense as I don't use the program regularly. I have been working on a file that is huge, 530 MB, and have been doing fine. I am now working on a file that is to be added to it, but it only about 3 MB in size. The problem I have is that I cannot do anything with it. Anytime I try to do a cut and paste or other action that increases or adds to it, it suddenly crashes. There is no Bugsplat. It simply just closes. I have no idea why. I've tried several workarounds such as making the added part a compenent then exploding it, but it still crashes. I've tried just adding the outline of the lines, trying to get that and manually add in the planes one by one. It still crashes. It doesn't do this on any other files except this particular one. I run two different computers which are more than enough to handle this thing.