Did you just get these machines? Were they sold by Bitmain or secondhand/used?

You can try installing a new firmware image. Go to https://shop.bitmain.com/support.htm?pid=00720161126080548570Q2tDBXAH065D and depending in which S9 machine you have, download the firmware. If it's not a static 14TH unit, then download the one at the bottom Antminer-S9-all-201708151137-autofreq-user-Update2UBI-NF.tar.gz.

Go to the miner's page under System tab -> Upgrade and under "Flash new firmware image" uncheck "Keep settings" and select the tar.gz firmware you downloaded.
Give it 5-7 minutes and then see if you can enter your pool info.