The normal situation like this. What's you Controller software version? And what's your computer system? Does your computer can work with the software? You need double check. Also f irewall and...

I don't think it will conflict between the 2 routers. You need to open two of them the DHCP. And you can try it by yourself. If you have solved, it will be better.

You just need to enable DHCP for the W8901N.

Maybe you should check your firmware version first. If your firmware version isn't the latest version, you could download from http://www.tp-link.com/en/download/EAP110_V1.html#Firmware then upgrate...

:):):D:D

I would also advise you to upgrade your EAP to the older version then upgrade to EAP120_V1_150709.