UPDATE:
Here are more details about why Justin Bieber's second concert in Portugal was canceled. According to the singer's team, it was all due to union rules in Portugal. Apparently it was strictly due to logistical issues -- NOT because of poor ticket sales -- as has been reported elsewhere. In fact, Bieber's manager, Scooter Braun, insists both shows were completely sold out. That was also confirmed by the local Portuegeuse promoters as well.
The problem was something called, "load out" -- the time allowed for the crews to break down the stage and sets and equipment from Bieber's show -- and get set up for the next one.
That said, after Justin Bieber's "week from hell" in England last week, the pop superstar's team has reportedly told him to calm down, focus on his music and his concerts and get enough rest -- hoping to prevent any future blowups (like he had with a papparazzo in London), or health scares, like his on-stage collapse and trip to the hospital.
Apparently a weekend intervention of sorts took place via phone, Skype and emails from key members of Team Bieber -- all orchestrated to help the singer move on from that bad week in London which has generated so many negative headlines.