I suppose out of memory could be possible depending on the mesh face count of your STL file and your set job size resolution (e.g. the 50x slower one).
For example I downloaded an "espresso cup" model from Thingiverse that measures: 65.061 by 85.595 by 50.046 millimeters. Despite its small size it contains 59,000+ faces.
Having said all this, I just tried importing a 1,293,000 triangle STL file at "50x slower" and VCarve laughed at me. Mind you I do have 32gb machine.