Today it happened again, and I caught it. When the alarm triggered, the stream started and started fading in as configured. A few seconds later, though, it abruptly stopped (with a very brief jump to full-volume as it did so - this tends to happen when I stop the stream manually too) and the message appeared. Error code -46767.

This is a Nexus 5, and I have indeed recently upgraded to 5.x (CyanogenMod 12, previously 11), so that matches up.

Edit: 5.0.2 specifically - the 20150219 nightly of CM12.

Unfortunately, when I saw the message in my half-asleep state I didn't think to take a screenshot, and I haven't seen it since. It seems it was a transient failure. If it happens again I will make sure to note down the number.

My request was more of a general safety feature to allow alarms to work (perhaps in a dumb/non-streaming mode) even if the license check fails though; this should be independent from the actual cause of the license failure.