Wireless clients (phones, laptops) cannot connect to the wifi anymore after the upgrade to the last firmware.
I have tried everything, changing wifreles parameters and configuration of the router, forgetting connections and checking wifi settings on the phones, etc (security, encryption, smartconnect, password, ssid names, optimizations and options on the phones) and nothing helped. All devices acted as if something is wrong with the authentication (constant reprompting to enter password on the laptops, sometimes an "authorisation error" on the phones is displayed when new connection is attempted.
The only way any of my devices can connect to wifi is when no security is set on the device (open network, without authentication).
Everything worked as expected before the last firmware upgrade. I tried to downgrade it but that's not possible (apparently).
I'm desperate for an urgent solution. Please help!