Error on transformation of file which is considered as valid by csvlint

[l00mi]

Any hints?

ERROR invalid byte sequence in US-ASCII
/usr/local/lib/ruby/gems/2.3.0/gems/rdf-2.1.0/lib/rdf/writer.rb:398:in write_epilogue': Errors found during processing (RDF::WriterError) from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-turtle-2.0.0/lib/rdf/turtle/writer.rb:193:in write_epilogue'
from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-2.1.0/lib/rdf/writer.rb:269:in initialize' from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-turtle-2.0.0/lib/rdf/turtle/writer.rb:131:in initialize'
from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-2.1.0/lib/rdf/writer.rb:199:in new' from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-2.1.0/lib/rdf/writer.rb:199:in block in buffer'
from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-2.1.0/lib/rdf/writer.rb:197:in open' from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-2.1.0/lib/rdf/writer.rb:197:in buffer'
from /usr/local/lib/ruby/gems/2.3.0/gems/rdf-2.1.0/lib/rdf/writer.rb:176:in dump' from /usr/local/lib/ruby/gems/2.3.0/gems/csv2rdf-0.2/lib/csvlint/csvw/csv2rdf/cli.rb:161:in transform_csv'
from /usr/local/lib/ruby/gems/2.3.0/gems/csv2rdf-0.2/lib/csvlint/csvw/csv2rdf/cli.rb:23:in transform' from /usr/local/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor/command.rb:27:in run'
from /usr/local/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor/invocation.rb:126:in invoke_command' from /usr/local/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor.rb:359:in dispatch'
from /usr/local/lib/ruby/gems/2.3.0/gems/thor-0.19.1/lib/thor/base.rb:440:in start' from /usr/local/lib/ruby/gems/2.3.0/gems/csv2rdf-0.2/bin/csv2rdf:9:in <top (required)>'
from /usr/local/bin/csv2rdf:23:in load' from /usr/local/bin/csv2rdf:23:in

'