WiFi range extender loses password and communication error
 

Advice needed please. I am using two TP link routers, TL-WR841HP, as range extenders in my house. One in the house and one in our cafe a small distance away. The other day I changed password for the one based in the cafe. I can log onto the cafe with my hand phone and so can my son. However after a short time the message comes up 'communication error'. The password does not work after that. To change the password I do a SAVE and then REBOOT when logged in to the house router for the Cafe signal. As I say for a short time the password is valid but changing it again has the same result. Both routers are about a year old and up to now no problems. The Guest feature is used on the house and is still OK with its own password unchanged. The modem into the system is an optical one and seems OK. Any help or thoughts much appreciated.

I recently had a similar problem with one of my wireless extenders.

I found there was a small, recessed "factory reset" button which needs a paper clip end to press. Doing so cleared the problem but I had to again "pair" the extender to the sender, using the factory instructions.