The warning occurs if the tools are being run at a time past the license version limit. For example, the following INCREMENT entry in a license file indicates a June 2011 version limit:
INCREMENT System_Edition xilinxd 2011.06 permanent uncounted
Running any licensed System Edition application released before the end of June 2011 will issue this warning if the 2011.06 limited license is the only license available.
As the warning indicates, the tools will continue to work. However, future updatesof the tool (released after June 2011) will not be enabled by this license and thus the later versiontools will not work.
See also:Licensing - What license
version limit is required for my Xilinx Software or IP core?
(Xilinx Answer 33770).