When trying out ZMQ on an embedded device with Windows Embedded Compact 7, we discovered timer events were never firing.
After some debugging we traced this down to the now_us calculation in clock.cpp. On our device, ticksPerSecond.QuadPart is < 1000000 making ticks_div zero and resulting in an invalid time.
double ticks_div = (double) (ticksPerSecond.QuadPart / 1000000);
return (uint64_t) (tick.QuadPart / ticks_div);
Windows Embedded Compact 7 (WEC7), ARM device