Intel Centrino Wireless-N 2230 won't connect, keeps asking for password [duplicate]

I'm on Kubuntu 16.04, all packages up to date.

Yesterday, out of the blue (not after a reboot or anything), my WiFi stopped working. The hardware is still working, I am able to connect over Ethernet, and all the local WiFi networks are listed in the NetworkManager widget. But when I try to connect to my WiFi network, it says "Configuring interface...", asks for a password, stalls for a moment, asks again, and so on, over and over again, never connecting.

I have already rebooted many times, installed all updates, and tried deleting and adding the connection, marking the connection as "Available to all users", and disabling kwallet.

EDIT: Here's the output of lspci -knn | grep Net -A3:

02:00.0 Network controller [0280]: Intel Corporation Centrino Wireless-N 2230 [8086:0887] (rev c4)
    Subsystem: Intel Corporation Centrino Wireless-N 2230 BGN [8086:4062]
    Kernel driver in use: iwlwifi
    Kernel modules: iwlwifi

The fix from this question, suggested by user68186, works for me (I'm able to connect to WiFi, thank you!).

So here's my updated question: is there a way for me to make WiFi work without disabling 802.11n speeds?

You need to set a kernel module option. Run in a terminal

sudo tee /etc/modprobe.d/iwlwifi-opt.conf <<< "options iwlwifi 11n_disable=8"

and reboot.

That sets the enable agg TX option for the iwlwifi module. This is required for this adapter to work in 802.11n mode well.