When taking Docker tutorials, one of the first things that pops up is running a web server in a container via Nginx. However, when you map ports (e.g. 80 on 80) you might get the following error:
Error response from daemon: driver failed programming external connectivity on endpoint <your container>: Error starting userland proxy: mkdir <ip:port mapping> : input/output error
The easy way to solve this problem is simply by restarting Docker. However, if you’ve had this error, you’ll run into it again.

For now, there’s no real solution, but there is a way to circumvent it: disabling fastboot. Your computer will take more time to boot, but you won’t run into the same error again.
