Get the new intermediate certificates

If you have followed other (incorrect) instructions to replace the 'omega.contacts.msn.com' certificate, then you must delete that certificate from Tools->Certificates first.

Download Microsoft_Internet_Authority_2010.pem and Microsoft_Secure_Server_Authority_2010.pem then follow the appropriate set of directions below.

Windows

• Save the files to C:\Program Files\Pidgin\ca-certs (or C:\Program Files (x86)\Pidgin\ca-certs as appropriate)
• Restart Pidgin

Linux

• Save the files to /usr/share/purple/ca-certs (or /usr/local/share/purple/ca-certs as appropriate)
• Restart Pidgin

Thanks to Kaurin/SQuID for blogging this solution earlier.