stanfordnlp/CoreNLP · error · RuntimeException

Error reading saved links

Error message

Error reading saved links

What it means

FromFileCorefAlgorithm reads gold coref merges from a file in its constructor and wraps any IOException in RuntimeException("Error reading saved links"). It treats the merge-link file as mandatory input that must be readable.

Solutions

1. Verify the path to the links file is correct and the file exists at runtime (print/resolve the path)
2. Run the JVM from a working directory where the relative path resolves correctly, or use an absolute path
3. Check file read permissions
4. Validate the file format (pairs like 'id1,id2' lines) — malformed content can also trigger the wrapped exception

Example fix

// before
props.setProperty("coref.algorithm.file", "links.txt");
// after
File f = new File("/abs/path/links.txt");
if (!f.canRead()) throw new IllegalArgumentException("links file missing: " + f);
props.setProperty("coref.algorithm.file", f.getAbsolutePath());

String linksPath = props.getProperty("coref.algorithm.file", "");
java.io.File f = new java.io.File(linksPath);
if (linksPath.isEmpty() || !f.isFile() || !f.canRead())
  throw new IllegalArgumentException("Coref links file not readable: " + f.getAbsolutePath());

try {
  FromFileCorefAlgorithm algo = new FromFileCorefAlgorithm(props, dictionaries);
} catch (RuntimeException e) {
  if ("Error reading saved links".equals(e.getMessage()))
    throw new IllegalStateException("Check coref links file path/contents", e);
  throw e;
}

When it happens

Trigger: Constructing FromFileCorefAlgorithm when the file of saved coref links cannot be opened/read — missing file, wrong path, or unreadable contents (IOException from the readLines/consumer processing).

Common situations: Wrong value for the coref algorithm file property (typo or relative path resolved against unexpected working directory); file deleted or not packaged with the model distribution; running from a different CWD.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• edu.stanford.nlp.io.RuntimeIOException
• Error creating data exporter
• Error setting up training
• RuntimeException wrapping IOException
• RuntimeIOException wrapping IOException

AI-assisted analysis of stanfordnlp/CoreNLP@1b7edd19c4 (2026-09-10). Data as JSON: /api/errors/00e7ccc5393b5f2d. Report an issue: GitHub.

Appendix: source

Thrown at src/edu/stanford/nlp/coref/misc/FromFileCorefAlgorithm.java:53

        String[] split = line.split("\t");
        int did = Integer.valueOf(split[0]);

        List<Pair<Integer, Integer>> docMerges = toMerge.get(did);
        if (docMerges == null) {
          docMerges = new ArrayList<>();
          toMerge.put(did, docMerges);
        }

        if (split.length > 1) {
          String[] pairs = split[1].split(" ");
          for (String pair : pairs) {
            String[] ms = pair.split(",");
            docMerges.add(new Pair<>(Integer.valueOf(ms[0]), Integer.valueOf(ms[1])));
          }
        }
      });
    } catch (IOException e) {
      throw new RuntimeException("Error reading saved links", e);
    }
  }

  @Override
  public void runCoref(Document document) {
    if (toMerge.containsKey(currentDocId)) {
      for (Pair<Integer, Integer> pair : toMerge.get(currentDocId)) {
        CorefUtils.mergeCoreferenceClusters(pair, document);
      }
    }
    currentDocId += 1;
  }

  public static void main(String[] args) throws Exception {
    Properties props = StringUtils.argsToProperties(new String[] {"-props", args[0]});
    new CorefSystem(new DocumentMaker(props, new Dictionaries(props)),
        new FromFileCorefAlgorithm(args[1]), true, false).runOnConll(props);
  }

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