protected Set<File> findJarsWithOldNamingConvention() {
    return Stream.of(deployDirectory.listFiles())
        .filter((File file) -> isOldNamingConvention(file.getName())).collect(toSet());
  }
Make sure that the deploy directory is writable.

@throws IOException If the directory isn't writable
geode-deployment/geode-deployment-legacy/src/main/java/org/apache/geode/deployment/internal/JarDeployer.java