Have you already tested newer firmware to see if it fixes the issue? The latest firmware can be downloaded from here:
https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux- firmware.git/plain/iwlwifi-3168-29.ucode Then you need to place the file in /lib/firmware. I recommend you keep a backup of the old file: # mv /lib/firmware/iwlwifi-3168-29.ucode /lib/firmware/iwlwifi-3168-29.ucode.orig # mv iwlwifi-3168-29.ucode /lib/firmware Then reboot to start using the new firmware. Let me know if that fixes the issue. If not, I suggest you follow up filing a bug as Emmanuel suggested as only Intel can help you resolve this issue. ** Changed in: linux-firmware (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1825993 Title: iwlwifi microcode error detected using hostapd with Intel 3168 in a NUC6CAYH To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1825993/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
