If you keep getting cannot find server error in Chrome browser but the WiFi network works fine, that might be caused by DNS cache which stores the IP addresses of pages you recently viewed. When the DNS cache is not updated and the location of the page has been changed, you are unable to visit the webpage.
How to flush and reset dns cache on nexus 7
* Doing a hard reboot of your tablet. Shut down the device, remove the battery. Wait for about 30 seconds, replace the battery and power up N7.
* You can also clear it by going Settings > Wireless & networks > More, turn Airplane mode OFF and then ON again.