MCE hardware error cpu 0

1.0 Error

ErrorWhile running Ubuntu 18.04.1 on a laptop, the following errors were observed.
mce: hardware error cpu 0 machine check 0 bank 6 ae0000000040110a
mce: hardware error tsc 0 addr ffb07540 misc 238a0000086
mce: hardware error processor 0:40651 time 1540082330 socket 0 Apic 0 microcode 24
ipmi dmi invalid offset 0
The system would stop in the single user mode.… Read more

Failed to fetch webpage, temporary failure resolving domain

1.0 Error

While configuring a Linux server, the error Failed to fetch webpage, temporary failure resolving domain was observed.

$ sudo apt-get update
Err:1 http://mirrors.xxxxxx.com/ubuntu bionic InRelease
  Temporary failure resolving 'mirrors.xxxxxx.com'
Err:2 http://mirrors.xxxxxx.com/ubuntu bionic-updates InRelease
  Temporary failure resolving 'mirrors.xxxxxx.com'
Err:3 http://mirrors.xxxxxx.com/ubuntu bionic-backports InRelease
  Temporary failure resolving 'mirrors.xxxxxx.com'
Err:4 http://security.ubuntu.com/ubuntu bionic-security InRelease
  Temporary failure resolving 'security.ubuntu.com'
Reading package lists...
Read more

SSL Certificate expired, site not opening

1.0 ERROR

A website stopped opening in browser, giving the error that the SSL certificate was either invalid or had expired.

2. SOLUTION

Checking the website with wget,

$ wget https://www.example.com
--2018-01-14 16:58:36--  https://www.example.com/
Resolving www.example.com (www.example.com)... 198.51.100.12, 2001:db8:1221:2341:f03c:f27b:12fa:2123
Connecting to www.example.com (www.example.com)|198.51.100.12|:443...
Read more