Did you try restarting the extender. It had been working great until yesterday all of a sudden yesterday there was no internet.

Reset Linksys Extender How To Reset Linksys Range Extender
Wifi extender stopped working. Extender stopped working after firmware update i did a paperclip reset then i needed to attach the extender to the router via ethernet cable. Turn off the wireless function and directly connect your computer to the router with an ethernet cable. The following product support and knowledge base article links are to assist with troubleshooting netgear wi fi range extenders. Others on this thread can connect to the extender network but are having trouble reaching the internet or their router. You could also try resetting the extender and then setting it up again. Make sure the extender is within the wi fi range of the wireless router and client device is connected to the extenders.
Range extender no longer working i have been using a range extender for the past couple of years but it is no longer working. Our network extender just stopped working today for no apparent reason. Reboot the computer and check for an internet connection. For installation and setup assistance see installing and configuring netgear wifi range extenders. Netgear ex2700 wifi extender suddenly stopped working. The main modemrouter is functioning but when i go through the setup process by pressing the wps buttons on both it seems to kick the wifi signal off of the router and extender.
Could this be due to the verizon maintenance going on this weekend. Actually your symptom sounds a bit different. I saw the announcement on vw site. If its asking for email. User manuals and firmware updates for netgear products can be downloaded from netgear supportfor more information see how to update firmware on your netgear product. Ive spent 3 days trying to figure out the problem but i am really out of my depth.
If not please send some suggestions. Im hoping theres something obvious. You arent able to connect to the extender network. I was able to reset the tp link to factory defaults and set it up again but the problem persists. Make sure the extender is connected to the power adapter provided and into a live power outlet. My tp link range extender has stopped working after 6 months without problems.
I tried the factory setting and the extender is fine but the router had issues and cannot connect to the internet. I was then able to access the setup menu from an internet browser on my computer and downgraded the firmware. If the router has been connected to the internet and worked in the past confirm the signal from your internet service provider isp is not the problem. Hi i bought a netgear ex2700 wifi range extender on 7th july 2018. Please let me know if this could be the cause.