If you are running the Dassault Systèmes license service (DSLS), up to R2014X, for Catia or Enovia CAD program/s, avoid or uninstall Windows Update KB 3061518.
Agreed, when the MS patch KB3061518 is applied to a Catia client machine, it loses connectivity to the DSLS license server. Once we updated the DSLS license server to version V6R2015x.FP.CFA.1517, this issue went away.