The curse of “Tosca” continues.

Starting with the boos that rained down on a pared-down production debut Monday, the Metropolitan Opera presentation seems to have suffered a string of bad luck.

Baritone George Gagnidze sang Scarpia in the first act last night but was feeling congested and acted the second while Carlo Guelfi sang from the side of the stage.

And music director James Levine missed last night’s performance because of a back ailment; Joseph Colaneri replaced him.