# pickle.UnpicklingError

- **ID:** `python/pickle-unpicklingerror`
- **Domain:** python
- **Category:** encoding_error
- **Verification:** official
- **Fix Rate:** 80%

## Root Cause

Unpickling failed. Corrupted data, security restriction, or incompatible version.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| 3.x | active | — | — |