2. Microsoft Windows Azure, Again
On Feb.28-29, Microsoft Windows Azure suffered an extensive, worldwide outage that lasted more than 24 hours for some users and was caused by what has become known as the "leap year bug."
Microsoft said the outage was caused by a software bug related to a "time calculation that was incorrect for the leap year," which apparently threw off digital certificates used to authenticate critical internal systems.
Some customers reacted angrily, saying Microsoft failed to communicate adequately.
"What I've noticed is a complete lack of estimates on issues will be resolved. What is the reasons behind Microsoft not informing its customers when the issue will be resolved?" Nitramafve wrote on an Azure chat board.