Thanks for posting.
Just to verify, does the crash occur exactly after you click 'Next' or 'Continue' after entering the License Key? If the installation continues, are you able to see what file the install is continually crashing on?
Also, are you installing FMP 7 and then installing FMP 8.5 or are you only installing FMP 8.5's media? If you're going from FMP 7 to FMP 8.5, try just using the FMP 8.5 installer. Make sure that the 8.5v2 patch is installed prior to launching FMP 8.5.
I would also try creating a new account and seeing if this will help.
Let me know how it works out.
I am installing FMP 7 and then installing FMP 8.5 and it crashes on 'Next' after entering the license key. This also happens when I try to install 8.5v2. I've downloaded FMP 9.0 demo and it has installed successfully. A colleague had the exact same issue when trying to install to her MacBook with Leopard OS.
Unfortunately, I've had to purchase 2 additional seat licenses for FMP 9.0 to not halt production.