Soyuz MS-02 has been undergoing preflight processing at Baikonur Cosmodrome, and the three crewmen (Sergey Ryzhikov, Andrey Borisenko, and Shane Kimbrough) had flown to Baikonur to begin preflight activities pending launch on Friday. However, the launch has now officially been delayed indefinitely, and the three have flown back to Star City, outside Moscow. The spacecraft, s/n 732, was encapsulated in its payload fairing and returned to its vertical position for additional fit checks prior to integration with the Soyuz-FG rocket. However, during those tests a short circuit was detected. The short apparently was caused during encapsulation, since the spacecraft had passed testing prior, but unfortunately it will not be possible to locate the short without removing the fairing. This alone sets the schedule back. Roscosmos has estimated that if the short turns out to be in the orbital module, it will take weeks to fix, but if it’s in the service module, it could take months. In that case, they’d likely go to plan B and start processing spacecraft s/n 733 for the Soyuz MS-02 mission, and buy a little more time to get 732 fixed and ready to fly as Soyuz MS-03.
The ISS currently is on a skeleton crew, as the current crew of three awaits the next inbound Soyuz crew. There is no timetable yet for when that will change. It does underscore the need for a second crew transfer method, but neither CST-100 or Dragon is likely to be ready before 2018.
(reference: Anatoly Zak’s RussianSpaceWeb blog)