DST Root CA X3 Expired September 2021 – FIX / Solution for all

On September 30 2021, most of the old internet connected devices reported issues in connecting websites and online services after the DST Root CA X3 certificate expired, especially those using Let’s Encrypt SSL certificates. This is not the first time that an incident like this is happening. On May 30 2020, the AddTrust External CA […]

cp – cannot create regular file : permission denied (root)

Here is the solution for the unexpected error cp – cannot create regular file : permission denied even when the user is logged into ubuntu or other linux server as root. Solution: Check if you are really superuser with: if the output is root, then you are superuser and you can make the copy of the […]