Ah. So I ought to revert to Mac OS 10.4.11 then, since upgrading to FM 8.5v2 is not an option for me right now.
Thank you for your post.
I have installed FileMaker Pro 8.0v2 on my iMac 2.4 GHz Intel Core 2 Duo running Mac OS X 10.5.8, and it launches fine. Therefore, I don't think the problem is with FileMaker Pro 8.0v2.
First, create a new user account, log in to that user account, and try launching FileMaker Pro 8.0v2. Does this work? If so, then there is something in the original user account that is conflicting with FileMaker Pro. If this doesn't work, then I would try uninstalling and reinstalling FileMaker Pro 8.0v2 and try again. If it fails again, see if you can get access to another machine with Mac OS X 10.5.8 and install on that machine. If that is not an option, then consider reinstalling Mac OS X 10.5.8 again and reinstalling FileMaker Pro 8.0v2. If this still fails, then reinstall Mac OS X 10.4.11 and return to your previous system.
Please keep us updated with any progress in case other forum members are reading this thread.