iwlwifi Wifi Microcode SW error detected (Ubuntu 18.04 x64)
Solution 1:
Try to create a configuration file, like so:
echo "options cfg80211 cfg80211_disable_40mhz_24ghz=Y" > /etc/modprobe.d/cfg80211.conf
Solution 2:
Had similar issues with Wi-Fi Link 5100.
The firmware (reliably) hangs when performing iperf3 transmit tests.
The solution was to disable TX aggregation.
options iwlwifi 11n_disable=2
Other answers on the internet suggest using 11n_disable=1 but that disables 802.11n entirely.