Public bug reported: I'm experiencing the exact same symptoms as this bug:
https://bugs.launchpad.net/ubuntu/+source/intel-microcode/+bug/1759920 However, that bug was marked as fixed. The workaround as desribed in that bug works for me. As soon as I try to update intel-microcode, my computer will not boot. I'm using the 4.4 kernel from 16.04. $ lsb_release -rd Description: Ubuntu 16.04.4 LTS Release: 16.04 $ apt-cache policy intel-microcode intel-microcode: Installed: 3.20180312.0~ubuntu16.04.1 Candidate: 3.20180312.0~ubuntu16.04.1 Version table: *** 3.20180312.0~ubuntu16.04.1 500 500 http://us.archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu xenial-security/main amd64 Packages 100 /var/lib/dpkg/status 3.20151106.1 500 500 http://us.archive.ubuntu.com/ubuntu xenial/restricted amd64 Packages $ uname -a Linux thinkpad 4.4.0-119-generic #143-Ubuntu SMP Mon Apr 2 16:08:24 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux $ dpkg -l | grep linux-image-4 | grep ^i ii linux-image-4.4.0-112-generic 4.4.0-112.135 amd64 Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii linux-image-4.4.0-119-generic 4.4.0-119.143 amd64 Linux kernel image for version 4.4.0 on 64 bit x86 SMP ii linux-image-4.4.0-122-generic 4.4.0-122.146 amd64 Linux kernel image for version 4.4.0 on 64 bit x86 SMP $ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 58 model name : Intel(R) Core(TM) i5-3317U CPU @ 1.70GHz stepping : 9 microcode : 0x1c cpu MHz : 893.761 cache size : 3072 KB physical id : 0 siblings : 4 core id : 0 cpu cores : 2 apicid : 0 initial apicid : 0 fpu : yes fpu_exception : yes cpuid level : 13 wp : yes flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc arch_perfmon pebs bts rep_good nopl xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm epb retpoline kaiser tpr_shadow vnmi flexpriority ept vpid fsgsbase smep erms xsaveopt dtherm ida arat pln pts bugs : cpu_meltdown spectre_v1 spectre_v2 bogomips : 3391.94 clflush size : 64 cache_alignment : 64 address sizes : 36 bits physical, 48 bits virtual power management: ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: intel-microcode 3.20180312.0~ubuntu16.04.1 ProcVersionSignature: Ubuntu 4.4.0-119.143-generic 4.4.114 Uname: Linux 4.4.0-119-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.20.1-0ubuntu2.16 Architecture: amd64 Date: Sat May 5 06:44:15 2018 InstallationDate: Installed on 2014-05-08 (1457 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417) ProcEnviron: LANGUAGE=en_US TERM=xterm PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash SourcePackage: intel-microcode UpgradeStatus: Upgraded to xenial on 2016-08-05 (637 days ago) ** Affects: intel-microcode (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug xenial -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1769335 Title: PC won't boot with latest intel-microcode To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/intel-microcode/+bug/1769335/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs