Xilinx ISE with Synplify Synthesizer

Im’ using the Xilinx ISE 9.1 with the Synplify Synthesizer 8.6.2, but I have some errors with the Endpoints WireIn and WireOut.
This is the error: “…No architecture is available for entity okwirein/okwireout”.

I think it’s because the synthesizer can’t use the black-box .ngc files.
Has anyone used the Synplify Synthesizer with the OpalKelly interface?
Thanks a lot!