I had this same error on a 3.14 kernel.
I fixed it by adding "CONFIG_DEVPTS_MULTIPLE_INSTANCES=y" to the kernel config.
I don't know what kernel version you're using, but maybe this helps.
If you look at https://github.com/moby/moby/blob/master/contrib/check-config.sh, it looks like that option is needed on kernels older than 4.8.