We can only help you if you give us full information.
1. What is the full exact message? And which Browser are you using? 2. Are you in router mode or modem mode? 3. If modem mode, which router are you using? 4. If router mode, is this WiFi or Ethernet? 5. Which operating system is this?
I've seen this before, though with the hub in modem mode. Something glitched and no wireless connection could be made. The browser on each wireless device brought up a message of the type you've described.
A wired connection (Ethernet) contiinued working. I had to reboot the external router and the hub in that sequence to restore the connection and avoid the message.
It seems from your answer that you are in router mode. So I asked you if the connection works when a device is wired to the Hub. You haven't answered that or maybe you have no Ethernet cable to try that.
SO the only advice left that I can offer is on Windows 10 go to the Command Prompt Window. Issue the following two commands in sequence: IPCONFIG /RELEASE IPCONFIG /RENEW
That should release the erroneous IP address range and then renew it based on your connection when you next try to wireless connect.