RuntimeError: Cannot open file. This file was likely created with Python 2 and an old hickle version.

[derelearnro]

File "/usr/local/lib/python3.6/dist-packages/hickle/hickle.py", line 526, in load
raise RuntimeError("Cannot open file. This file was likely"
RuntimeError: Cannot open file. This file was likely created with Python 2 and an old hickle version.

How can we debug in this situation above? It is problem of using python3 but unsupported from hickle.

hickle.py

 elif VER_MAJOR == 2:
                    if six.PY2:
                        warnings.warn("Hickle file appears to be old version (v2), attempting legacy loading...")
                        import hickle_legacy2
                        return hickle_legacy2.load(fileobj, safe=safe)
                    else:
                        raise RuntimeError("Cannot open file. This file was likely"
                                           " created with Python 2 and an old hickle version.")
                # There is an unfortunate period of time where hickle 2.1.0 claims VERSION = int(3)
                # For backward compatibility we really need to catch this.
                # Actual hickle v3 files are versioned as A.B.C (e.g. 3.1.0)