Update: The issues have been fixed, Bungie confirms.
Issues impacting players' ability to complete the Nightfall have been resolved. Thanks for your patience.
— Bungie Help (@BungieHelp) January 12, 2016
Original Story: Many Destiny players are reporting a bug in this week's Nightfall strike is preventing them from completing the event.
This week's strike is Sunless Cell, which ends with the Darkblade boss fight. Players are unable to get that far, however, as the door to reach the ogre remain closed. Reports also suggest that enemies aren't spawning during the strike's first half.
The problems persist even after users reset, return to orbit, and boot all other players bar the host.
Bungie has confirmed that they're aware of the problems and are currently looking into resolving them.
We are aware of reported issues with the weekly Nightfall and are investigating. Please stand by.
— Bungie Help (@BungieHelp) January 12, 2016
In other Destiny news, it seems Mercury may be the focus of the next in-game event, which appears to be called 'The Dawning'.