This answer record details the known issues related to the Xilinx implementation of FLEXnet licensing for the 2012 Vivado and 14.x ISE Design Suite release.
For general questions about software licensing, see the following Xilinx Licensing FAQ page.
Xilinx Licensing Site:
Outstanding Known Issues in ISE Design Suite 14.7
(Xilinx Answer 30526) - FLEXnet fails to find license when the computer default network interface is "eth1" (instead of "eth0")
(Xilinx Answer 33026) - Xilinx License Configuration Manager (XLCM) might take a long time to load the available licenses
(Xilinx Answer 33719) - XLCM shows only one available seat when a license file contains multiple entries of a feature
(Xilinx Answer 52412) - A "license was not found for the XPS feature is issued even though a valid xps_tdp feature is found
(Xilinx Answer 52723) - XLCM does not handle paths with Simplified Chinese characters
Issues Resolved in ISE Design Suite 14.7
(Xilinx Answer 56505) - The HOST ID matches column in XLCM is incorrectly shown as "No"
(Xilinx Answer 35616) - A floating Partial Reconfiguration license must be on the same server as PlanAhead license in order to be found
Issues Resolved in ISE Design Suite 14.6
(Xilinx Answer 55509) - FlexID-9 Hardware USB Dongles are not recognized by Vivado 2013.1 or ISE 14.5 design tools
Issues Resolved in ISE Design Suite 14.5
ISE Design Suite 14.5 converted to using FLEX version 11.11 for Licensing (ISE Design Suite 14.4 uses FLEX v11.6)
Issues Resolved in ISE Design Suite 14.4
Issues Resolved in ISE Design Suite 14.3
(Xilinx Answer 40252) - The "Host ID Matches" Column is not correct when Disk Serial Number is used
(Xilinx Answer 51222) - Vivado gives a license error when generating Top Level HDL Wrapper for EDK/Platgen