My iPad mini has been working flawlessly since Christmas, 2016 (13 months). I used it for over an hour last night. This evening, it suddenly decided that it doesn't like the wifi password, which hasn't changed in several years and which 5-6 other devices use all the time. After it tells me that the password is invalid (I tried it very carefully several times), I get a message that says something like, "WEP is not secure. Reconfigure the router for WPA2 Personal (AES).".
The router is in a closet in my home. Only two people li ve here and no one has touched it in weeks or months, let alone since last night.
Can anyone explain what is going on and how to get it to behave?