My internet on my MacBook Pro isn't working due to a "WAN Connectivity Issue"

So earlier the wifi on my MacBook Pro stopped working. I can connect to the wifi but it wont load anything. I ran a wireless diagnostics test and it said I have a WAN Connectivity Failure. It says that the wifi connection is good but the wireless router can't connect to the Internet. I don't think this can possibly be correct as the wifi is working perfectly for every other device. What can I do to fix this error and get back online?