@Tony - Thank you. Will give it a go.

@Tony 

I have the same issue but when I try to log on to my Range Extender Model RE650 using http://tplinkrepeater.net/ I sometimes get access and sometimes I get the "Trying to Configure the Range Extender? It looks like you may have run into an issue" error message.

When I do get connected to the RE, it stops me from selecting the different options available (like stops me from getting to Wireless > Wireless Settings > Advanced).

Playing around later I get access to the RE again but then have problems getting to different options again.

Any ideas?

@Tony 

It has gotten somewhat stable now when I log on to my Range Extender Model RE650 using http://tplinkrepeater.net/.

Unfortunately, I only see options "Connect to Network" and "Extended Network" under "Wireless". I don't see the Wireless > Wireless Settings > Advanced option.

@Gerard007 

The screenshot in post #9 refers to a router since you have an extender, mainly the RE650, we have a firmware you can upload that will give the AES option: 

https://static.tp-link.com/2020/202010/20201012/re650v1_en-up-ver1-0-8-P1[20200922-rel60445].zip

@Tony 

Thank you SO much, Tony. That worked perfectly on my RE650. I no longer get the message "WPA/WPA2 (TPIK) is not considered secure. If this is your Wi-Fi network, configure the router to use WPA2 (AES) or WPA3 security type." on my iPhone.

I don't know what I would have done without you; I don't think it is common knowledge that this firmware is available for the RE650.

Thank you again. Have a great weekend.

@Tony 

BTW, I overcame the instability of using http://tplinkrepeater.net/. I was sometimes getting access and sometimes I was getting the "Trying to Configure the Range Extender? It looks like you may have run into an issue" error screen.

I determined the ip address of my RE650 on my network and connected directly to that ip address instead of using http://tplinkrepeater.net/.

Thank you SO much again.

@Tony

I'm using RE450 (V2), firmware is up-to-date.

Upgrade to IOS 14 required me to change router to WPA2 (AES) but this setting is not availabe on my RE450, making it unusable.

Product is just 2 years old.

What can I do?

Thanks in advance

@Celticmist 

Not being able to set AES does not make the product unusable, you just keep getting the warning message from any iOS device. Similar to a website site not having a signed SSL, you can still navigate to the site, but get hit with the warning.

You can try setting your router to AES only, then set up the extender again to see if that helps.

@Tony 

thanks for your attention.

The unit is unusable in the sense that I get no internet service from the Re450 when the router is set to AES.

The extender does not take the AES setting from the router and it does not allow me to set it manually through the web interface.

I notice this seems to be a feature in some extenders but not this one,

This was not a problem until all our devices were auto upgraded to IOS 14.1.

In this situation the device is unusable unless you have a solution?

@Celticmist 

I would reach out to your local support team as firmware is based on region. The RE650 received firmware for the AES option, but have no information regarding the RE450.