If I open a Project File (*.acc) created via AccelChip DSP, release 2006.1.0 or earlier, and that project file does not have a specified Vendor, or the Vendor is Other, I am unable to set a new vendor from within AccelDSP (release 8.1) GUI.
The solution is to type the following line in the Tcl Console:
SetProjectOption -techvendor Xilinx
Then, save the project and you will be up-to-date with the latest release.
Alternatively, you can set the Technology drop-down. In any case, your RTL must be targeted to a specific Xilinx part,.