TransparencyFactor and Opacity are a single value within an FBX file and according to the FBX SDK docs it should contain a value ranging from 0 (full opacity) to 1 (full transparent). But it seems like fbxsdk converts it to TransparencyColor anyway. Not sure if that's a 2014 feature or was in there before. Anyway, this should fix it.
TransparencyFactor and Opacity are a single value within an FBX file and according to the FBX SDK docs it should contain a value ranging from 0 (full opacity) to 1 (full transparent). But it seems like fbxsdk converts it to TransparencyColor anyway. Not sure if that's a 2014 feature or was in there before. Anyway, this should fix it.