Unfortunately, the DSP48 block we have created depends on some internal libraries only available in LabVIEW 2009. Now we could replicate those libraries in 8.6, however this is not trivial effort. If you have at least one copy of LabVIEW 2009, you can copy the VHDL instantiation from the property page of the DSP48 node. You could then paste the instantiation into an HDL node or CLIP in LabVIEW 8.6.