Thank you for your post.
This error message usually refers to a bad installation. Try uninstalling and reinstalling FileMaker Pro 8 again. Also, after installation, pull down the FileMaker menu and select "About FileMaker Pro". If you are not using FileMaker Pro 8.0v3, then download the update through Knowledge Base Article #6846:
If you have another Windows XP machine running FileMaker Pro 8, you can try copying the server.pem file from the FileMaker Pro folder on the working machine, and copy it into the FileMaker Pro folder on the non-working machine. The server.pem file controls the network sharing.
Failure to load network stack error
Reinstalling the older FileMaker Pro 8.5 or earlier after 2008 will cause this or similar error to display when connecting to the hosted files. The reason is a corrupted SSL Certificate because the end date is earlier than your install date. There are 2 ways to fix this:
1. If you have another workstation that is connecting properly to the host files navigate to its FileMaker folder and in the root section of that folder copy the 'server.pem' and the 'host.pem' files. Replace the problem workstations server and host files with these server and host files.
2. Uninstall the FileMaker Pro from the problem workstation. Then set that workstations date back to 2007. Then reinstall the FileMaker Pro software back on the workstation. After installing the FileMaker Pro you can then reset the date back to the current date.