FireFly in Poser 11 Added Gamma Correction (GC) for all people. It use to be Poser 10 and lower had Gamma Correction set at 1.0 and only those who had the Pro versions had Gamma Correction of 2.2. The easiest way to get all older scenes to work is to change the global setting to 1.0 instead of 2.2 in the Render Settings tab. Of course if you made changes to other parts you might run into issues with the wrong GC being applied.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13