Installation Problem in Quartus ii 9.1 SP2

What quartus II 9.1 edition were you installed? Is it web edition or subscription edition? Can you check it (helpàabout quartus II) in quartus II main window? To successfully install the Quartus II 9.1 sp2 patch, you should have quartus II 9.1 subscription edition installed on your PC.

Besides, do you point to correct Quartus II 9.1 directory while upgrading to quartus II 9.1sp2? If quartus II 9.1 is available in that path, then I suspect your quartus II 9.1 software might be corrupted. In fact, I faced the exactly similar issue previously.

By uninstalling the QII 9.1 & reinstall QII 9.1, I could successfuuly installing QII 9.1sp2.