Won't boot. udevd: worker not accepting message.

[linux guy]

I get hundreds of the following error when I boot any one of the
kernels on my F16 computer.

udevd[983]: worker [xxxx] did not accept mesage -1 (Connection
refused), kill it.


I also see

udevd[1215]  error opening
ATTR{/sys/devices/pci0000:00/0000:00:1a.0/usb3/3-1:1.0/power level}
for writing: No such file or directory.

When I log into maintenance mode, everything looks fine.  Boot.log is
clean.   Xorg.0.log is clean.  Drives mount properly and I can browse
them, no problem.

It appears that ubuntu had this problem a while back.

https://bugs.launchpad.net/ubuntu/+source/udev/+bug/647404?comments=all

What is causing it ?