Can you try accessing the APs IP via browser to see if it fails too or is it just unable to access over the app ?
On the administrative computer, open a web browser window.
In the address or location bar, type the following address:
Press Enter on the keyboard to connect to the AP's web interface. A security alert message appears.
Click Yes or OK or Proceed anyway (depending on the browser) to continue. The AP's login page appears.
In User name and In Password, put the credential.
Click Login. The web interface appears.