The download manager defaults to your older poser serial number. As soon as you start the download manager change the serial number to the Poser 11 serial....et voila. Also the content won't install until the Poser 11 is installed. I did reboot before continuing and the contents were reverified and installed. Still can't get the library to work at all.
Netherworks on RDNA has a workaround to use the old LSMGUI but it is not 100 percent.