The SSL certificate expired today.
Philip at Manjaro has this to say about it:
Expired SSL certificate
Seems we forgot to update our SSL certificate in time. This means our wiki and forum is not reachable for now. We will work on the matter as soon as possible. In time, please use followed workaround:
open a terminal
enter followed line: sudo date –set 2015-04-06 +09
This will set back your system time to Mo 6. Apr 00:00:03 CEST 2015
kind regards Philip Müller, Manjaro Development Team
This seems like a really bad idea to me though. Tampering with your system date can get you into trouble. Just my two cents
These things happen - and the distro is great - so it is forgivable that they forgot about the bureaucracy this time
If you browse to the manjaro forum with the Tor-browser then you will be able to accept an exeption so you can browse as you like.