Tree too deeply nested; IEER dataset

[tnmcneil]

I am trying to convert the NIST-IEER to CoNLL format and see the following error:
It looks like it gets through the first 6 files fine but only gets partway through NYT-19980407

Done with  APW_19980314
Done with  APW_19980424
Done with  APW_19980429
Done with  NYT_19980315
Done with  NYT_19980403
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "makeconll.py", line 109, in write_all_to_conll
    write_conll(filename)
  File "makeconll.py", line 100, in write_conll
    sentences = parse_doc(filename, index)
  File "makeconll.py", line 67, in parse_doc
    tags = tree2conll_without_postags(dt)
  File "makeconll.py", line 35, in tree2conll_without_postags
    raise ValueError("Tree is too deeply nested to be printed in CoNLL format")
ValueError: Tree is too deeply nested to be printed in CoNLL format

I am also wondering if there is a way to reconstruct the original text from the articles