Are you asking how to fix it, or just if someone else has had that happen? If the former, you need to check the cable, at the control and at the transmission. Sounds like it may have failed or become disconnected. It you can get to the attachment at the transmission, you should be able to change gears there (though that is a little scary if you are solo).
If the latter question is the one you are asking, there are lots of folks who have experienced a similar failure, so it's just a question of what gear the boat was in when the failure occurred. I was at the helm maneuvering on a friends Catalina 30, and lost the cable attachment at the transmission. I happened to be in neutral, but in desperate need of forward. (I guess reverse would also have been better than neutral in the particular circumstance, now that I think about it). It always happens at the worst possible time, or in the worst possible manner, so Plan B should be implementable instantly, and Plan C on standby.