# ValueError: The adapter configuration does not match the base model. Expected adapter type 'lora' but got 'ia3'

- **ID:** `huggingface/peft-adapter-config-mismatch`
- **Domain:** huggingface
- **Category:** config_error
- **Verification:** ai_generated
- **Fix Rate:** 88%

## Root Cause

Loading a PEFT adapter saved with one method (e.g., LoRA) onto a model that expects a different method (e.g., IA3), causing a configuration mismatch.

## Version Compatibility

| Version | Status | Introduced | Deprecated |
|---------|--------|------------|------------|
| peft>=0.5.0 | active | — | — |
| transformers>=4.30.0 | active | — | — |

## Workarounds

1. **Load the adapter with the correct PEFT method class explicitly.** (90% success)
   ```
   Load the adapter with the correct PEFT method class explicitly.
   ```
2. **Inspect adapter_config.json and set peft_type manually before loading.** (85% success)
   ```
   Inspect adapter_config.json and set peft_type manually before loading.
   ```
3. **Re-create the adapter using the correct method from scratch.** (70% success)
   ```
   Re-create the adapter using the correct method from scratch.
   ```

## Dead Ends

- **** — This flag only handles size mismatches, not adapter type mismatches. (95% fail)
- **** — The issue is not library installation but adapter metadata stored in the adapter_config.json file. (98% fail)