I'm seeing confirmation from several independent sources that Tuesday's Windows Schannel patch, KB 3061518, is preventing Catia and Enovia (both 3D CAD programs from Dassault Systèmes) from pulling licenses from the license server. Removing KB 3061518 fixes the problem.
I haven't seen official confirmation from Dassault or Microsoft, but the anecdotal evidence is overwhelming.
(t/h NS, SB, GB and Anonymous SANS ISC)