Does Luke 16:18 mean a man is an adulterer if he marries a woman who divorced her husband for reasons other than sexual infidelity?

“Every one who divorces his wife and marries another commits adultery, and he who marries a woman divorced from her husband commits adultery.” (Luke 16:18).

Regarding the issue of adultery and the meaning of this passage, let me encourage you to read the study on marriage and divorce at http://www.tyndale.cam.ac.uk/brewer/non-acad/intro.htm.