I've heard from a couple of people about problems reading Cadence display.drf files leading to crashes, due to the fact the parser fails to identify layers/stipples/packets in the file.
Unfortunately all the examples I have work fine, so if you hit a crash importing a Cadence display file / techfile, let me know, and if you can send an example display.drf which fails to read the layer info, that would help (they do not contain any design or process data btw).