G.fst error , bad FST header

[sarahalmunif]

hello , when i run script that build my own language model i had this error but i don't understand it can you help me

ERROR: FstHeader::Read: Bad FST header: standard input
arpa2fst -
LOG (arpa2fst[5.5.6032-4bbac]:Read():arpa-file-parser.cc:94) Reading \data\ section.
LOG (arpa2fst[5.5.6032-4bbac]:Read():arpa-file-parser.cc:149) Reading \1-grams: section.
WARNING (arpa2fst[5.5.6032-4bbac]:Read():arpa-file-parser.cc:139) Zero ngram count in ngram order 2(look for 'ngram 2=0' in the \data\ section). There is possibly a problem with the file.
LOG (arpa2fst[5.5.6032-4bbac]:Read():arpa-file-parser.cc:149) Reading \2-grams: section.
WARNING (arpa2fst[5.5.6032-4bbac]:Read():arpa-file-parser.cc:139) Zero ngram count in ngram order 3(look for 'ngram 3=0' in the \data\ section). There is possibly a problem with the file.
LOG (arpa2fst[5.5.6032-4bbac]:Read():arpa-file-parser.cc:149) Reading \3-grams: section.
remove_oovs.pl: removed 0 lines.
fstisstochastic /Users/saramuneef/kaldi/egs/maghnaAsr/data/local/lang/G.fst
ERROR: FstHeader::Read: Bad FST header: /Users/saramuneef/kaldi/egs/maghnaAsr/data/local/lang/G.fst
ERROR (fstisstochastic[5.5.603~2-4bbac]:ReadFstKaldiGeneric():kaldi-fst-io.cc:53) Reading FST: error reading FST header from /Users/saramuneef/kaldi/egs/maghnaAsr/data/local/lang/G.fst

[ Stack-Trace: ]
0 libkaldi-base.dylib 0x0000000106fa892f kaldi::KaldiGetStackTrace() + 63
1 libkaldi-base.dylib 0x0000000106fa86a2 kaldi::MessageLogger::LogMessage() const + 354
2 libkaldi-fstext.dylib 0x0000000106b95798 kaldi::MessageLogger::LogAndThrow::operator=(kaldi::MessageLogger const&) + 24
3 libkaldi-fstext.dylib 0x0000000106b95c1f fst::ReadFstKaldiGeneric(std::__1::basic_string<char, std::__1::char_traits, std::__1::allocator >, bool) + 879
4 fstisstochastic 0x0000000105df9bad main + 285
5 libdyld.dylib 0x00007fff6d69e7fd start + 1
6 ??? 0x0000000000000002 0x0 + 2