E-PE0001 — Unsupported schema version

Error Type

Protobuf Error

Phase

loading a model via protobuf (from_protobuf)

Python exception

jijmodeling.ProtobufError

Message

Unsupported schema version {version}: this JijModeling supports versions {minimum} to {maximum}.

Possible fix: if the version is above the supported range, update jijmodeling; otherwise re-export the model with a supported JijModeling release.

Cause

The serialized model declares a schema version outside the range supported by your installed JijModeling. Most commonly the model was produced by a newer JijModeling release than the one trying to load it. A reported version of 0 instead means the version field is absent: the input is empty or the bytes were not produced by JijModeling’s serializer.

Fix

If the reported version is above the supported maximum, upgrade JijModeling to a version that supports the model’s schema version:

uv sync --upgrade-package jijmodeling
# Or with pip: pip install -U jijmodeling

If the reported version is 0, check the byte source: make sure you are loading the exact, non-empty output of to_protobuf (binary mode, no re-encoding). If upgrading is not an option, re-export the model from the source using a JijModeling version within the supported range.