Files created by older versions of Filemaker such as FileMaker 4, often have very messy external data source references and may include formats that are not optimum for newer versions of FileMaker.
Open Manage | External Data Sources... and check to see what you have there. If you see an entry where asterisks are used, update this external data source so that these references are no longer needed.
If you see an IP address that isn't valid, remove or fix it.
Both of these issues can result in major delays when opening your file.