Well, the beginning of the metro closures for the Olympic and Paralympic Games is here.
As of tomorrow, Friday, May 17, the line 12 stop at Concorde metro station will be closed through September 21.
This means you can't change between lines 1 and 12 at Concorde, nor between lines 8 and 12 there.
You can still go north/south on line 12 -- it's just that the line 12 train will go through Concorde station without stopping.
The next set of closures (related to these pre-planned Olympics closures) is slated for June 17.