Tal vez deberías probar con la FileMaker 12 Standalone Converter
The FileMaker 12 Standalone Converter is designed to convert large .fp7 databases to the .fmp12 format. The Standalone Converter preserves the contents of your original files and creates new, converted files in FileMaker Pro 12 format. Databases converted by the database converter will be functionally identical to databases converted with FileMaker Pro.
Who should use this tool?
If your database is larger than 400MB, has 4 or more tables, and has a large number of indexed fields and value lists, then your database is a good candidate for use with the Standalone Converter. It is still possible to convert databases of this size with FileMaker Pro, but because the Standalone Converter is a 64-bit multi-threaded tool, converting large .fp7 databases to .fmp12 format may be faster using this tool.
If your database does not meet these criteria, convert your database using, at a minimum, FileMaker Pro 12.0v2 or FileMaker Pro 12.0v2 Advanced.
Aunque creo que sólo está disponible para socios de FileMaker Community.