@robindgraph , I reproduced the error from the file in https://spec.edmcouncil.org/fibo/ontology/master/latest/dev.rdf.zip (Got hint from FIBO-Development\FIBO-Development-essence\be\Corporations\Corporations.rdf) [RDF-XML]
This is RDF-XML format. But we support NQuad syntax for RDF.
This nquad format might work for you. Also, you may want to look at external ID (XID). This would be needed for your dataset.