At the risk of tempting fate, I'll say that I have yet to get a completely blank roll, although I've gotten some pretty thin results when I've experimented with totally unknown (to me) film/developer combinations. On a recent roll, I miscalculated the dilution and ended up with thin, but still printable, negatives.
Paul's comment about edge markings is likely, but not certain, to be correct. Foma bulk 35mm films lack edge markings, in my experience. Foma individual rolls do have edge markings, though, so this isn't true of all Foma films. I don't know of any other film that lacks edge markings, but there may be some examples, perhaps even including individual runs that lack markings because of manufacturing problems. (I vaguely recall reading a story here a while ago about some Ilford film that lacked edge markings.)
I've heard of people getting fixer and developer bottles mixed up. That'll result in a completely blank roll. Likewise if you accidentally use a blix instead of a fixer. I keep my color chemistry on a different shelf from my B&W chemistry to minimize the risk of the latter problem. Using different types of bottles can also help; if the fixer's always in one type of bottle and the developer is in another type, you're less likely to get them mixed up.