If settings in the IBERT Wizard version 2.02a are all selected together, the core will not generate properly.
1) The target device is a Virtex-7 2000T in the FHG1761 package.
2) External clock is unselected on the first page of the Wizard.
3) On the second page of the Wizard, the reference clock is chosen to be 100MHz .
4) The reference clock is sourced from Quad 119, refclk1.
5) IBERT is set to use Quad 119 (X0Y35) for TX and RX.
This is a known issue with IBERT 2.02a which will be addressed in future versions of the tools.