OWA or ECP ADFS error "wrongaudienceuriorbadsigningcert"

https://vandijk.cloud/ad-fs-for-ecp-or-owa-fails-with-error-wrongaudienceuriorbadsigningcert/

Offline IM for Skype and Lync

Offline IM -  a feature that allows you to get missed IM while you are offline is not avaiable for Lync 2013 server, but is for Skype for Business server: https://docs.microsoft.com/en-us/skypeforbusiness/deploy/im-and-presence/enable-or-disable-offline-im

PGP for Widows

https://www.gpg4win.de/thanks-for-download.html

Verify certificate with command line certutil.exe

The command to verify a certificate:

certutil -f -urlfetch -verify C:\temp\www.google.de.crt

https://www.admin-enclave.com/en/articles/windows/57-how-to-verify-the-certificate-chain-via-windows.html