> ## Documentation Index
> Fetch the complete documentation index at: https://fhenix-docs-broken-sample-fixes.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Common Errors

> Critical limitations and important considerations when working with CoFHE, including common issues and Solidity error references

## Overview

This page documents the limits and error messages you are most likely to meet when working with CoFHE, and what to do about each one.

<Warning>
  Always verify you're using compatible component versions. Many errors can be resolved by ensuring you're using the latest versions of all CoFHE components.
</Warning>

<Card title="Quick Error Decoding" icon="terminal" href="/fhe-library/reference/cofhe-errors">
  Encountering cryptic `execution reverted: 0x...` errors? Use the **@fhenixprotocol/cofhe-errors** package to decode them instantly:

  ```bash theme={null}
  npx cofhe-errors 0x118cdaa7
  ```

  See the [CoFHE Errors Package](/fhe-library/reference/cofhe-errors) documentation for usage, and the [Error Reference](/fhe-library/reference/cofhe-errors-reference) for the complete list. The package predates the current contracts, so a selector it does not know is not necessarily invalid: check the reference.
</Card>

## Common issues

### Missing revert data

If you encounter a `Missing revert data` error, verify that you're using the latest `cofhe-contracts` version.

<Steps>
  <Step title="Check your version">
    Verify the version of `cofhe-contracts` in your project:

    <CodeGroup>
      ```bash npm theme={null}
      npm list @fhenixprotocol/cofhe-contracts
      ```

      ```bash yarn theme={null}
      yarn list --pattern "@fhenixprotocol/cofhe-contracts"
      ```

      ```bash pnpm theme={null}
      pnpm list @fhenixprotocol/cofhe-contracts
      ```
    </CodeGroup>
  </Step>

  <Step title="Compare with compatibility guide">
    Check the [Compatibility](/get-started/introduction/compatibility) page to ensure you're using a supported version.
  </Step>

  <Step title="Update if necessary">
    If your version is outdated, update to the latest compatible version:

    <CodeGroup>
      ```bash npm theme={null}
      npm install @fhenixprotocol/cofhe-contracts@latest
      ```

      ```bash yarn theme={null}
      yarn add @fhenixprotocol/cofhe-contracts@latest
      ```

      ```bash pnpm theme={null}
      pnpm add @fhenixprotocol/cofhe-contracts@latest
      ```
    </CodeGroup>
  </Step>
</Steps>

<Note>
  This section will be expanded over time as new issues arise. If you encounter an issue not documented here, please report it to the Fhenix team.
</Note>

## Possible errors from Solidity

The errors below are the ones a contract can hit during normal development. Each comes with its selector so you can match it against an `execution reverted: 0x...` message. Admin, upgrade, and signature-parsing errors are listed on the [Error Reference](/fhe-library/reference/cofhe-errors-reference) page only.

### Access control

| Error | Description |
| - | - |
| **ACLNotAllowed** `0x4d13139e` | The caller is not allowed to use the handle. Call `FHE.allowThis` or `FHE.allow` on a value before another transaction, or another contract, uses it |
| **SenderNotAllowed** `0xd0d25976` | The account granting or sharing access does not itself have access to the handle. A contract can only allow what it is allowed to use |
| **DirectAllowForbidden** `0x3809a243` | The ACL was called directly instead of through the TaskManager. Use the `FHE.allow*` helpers |
| **NotShared** `0xa70a958e` | A contract tried to receive a shared value that was not passed to it in the same transaction. Pass values between contracts as `sharedEuintXX` |
| **UnexpectedSharer** `0x3a194b4f` | The shared value came from a different contract than the receiver expected |
| **NotOnAccessList** `0xb688c6f5` | The TaskManager access list is enabled and the calling contract is not on it. The list is disabled on the public testnets |

### Input validation

| Error | Description |
| - | - |
| **InvalidEncryptedInput** `0x67cf3071` | The encrypted input's type does not match the `FHE.asE*` conversion you called. Raised inside your contract by the FHE library |
| **InvalidSigner** `0x7ba5ffb5` | An encrypted input was not signed by the ZK Verifier, most often because it was encrypted for a different chain, contract, or account. Also raised when a decryption result was not signed by the Teecryptor |
| **InvalidSignature** `0x8baa579f` | A signature on an encrypted input batch or decryption result does not recover to any signer |
| **InvalidInputsAmount** `0x9a84351c` | The operation received the wrong number of encrypted inputs |
| **InvalidOperationInputs** `0xb31612aa` | The operation received no encrypted inputs, or plaintext extra inputs it does not take |
| **TooManyInputs** `0x2b0399d5` | The operation received more than three inputs in total |

### Types and security zones

| Error | Description |
| - | - |
| **InvalidTypeOrSecurityZone** `0x52b50ae1` | The two operands differ in type or security zone. Cast one side first |
| **InvalidInputType** `0x884a0e9d` | The condition passed to `select` is not an `ebool` |
| **InvalidInputForFunction** `0x91b4b378` | The operation does not accept this type: `eaddress` in arithmetic or comparison, `ebool` in numeric operations, or a plaintext that does not fit the target type in a plaintext conversion such as `FHE.asEuint8` |
| **InvalidSecurityZone** `0x24cbcf36` | A handle or input's security zone is outside the configured range |
| **SecurityZoneOutOfBounds** `0x8f568bf8` | A negative security zone was passed to a plaintext conversion. Raised inside your contract by the FHE library |
| **UnsupportedType** `0xcabe5ce4` | The requested return type or cast target is not a valid encrypted type id |

### Decryption

| Error | Description |
| - | - |
| **DecryptionResultNotReady** `0x70cf6554` | `getDecryptResult` was called before the result was published. Use `FHE.getDecryptResultSafe` to poll without reverting |
| **DecryptFunctionNotSupported** `0x31a7e7ab` | The `decrypt` function id was submitted as a task. Request decryption through the SDK and verify it onchain with `FHE.verifyDecryptResult` |
| **RandomFunctionNotSupported** `0x98e08ab0` | The `random` function id was submitted as an ordinary task. Use `FHE.randomEuint32` and the other `randomE*` helpers |
| **LengthMismatch** `0xff633a38` | The handle, result, and signature arrays passed to a batch decryption call have different lengths |
| **CofheIsUnavailable** `0xd8aba367` | An admin has disabled the coprocessor. Task creation and result publishing revert until it is re-enabled |

### Access Control Permissions

These four errors come from the Access Control Permission (ACP) check in the ACL. They surface when an ACP presented for decryption is rejected.

| Error | Description |
| - | - |
| **PermissionInvalid\_Expired** `0xed0764a1` | The ACP has expired. Create a new one |
| **PermissionInvalid\_IssuerSignature** `0x4c40eccb` | The issuer signature does not verify |
| **PermissionInvalid\_RecipientSignature** `0x8e143bf7` | The recipient signature on a sharing ACP does not verify |
| **PermissionInvalid\_Disabled** `0xcbd3a966` | The revoker contract reports the ACP as revoked |

### Where to look first

* **Access control errors** almost always mean a missing `FHE.allowThis` or `FHE.allow` in an earlier transaction. See [access control](/fhe-library/core-concepts/access-control).
* **Input validation errors** usually mean the encrypted input was produced for a different contract, account, or chain. Re-encrypt with the consuming contract set.
* **Type errors** mean the two sides of an operation do not match. Cast with `FHE.asEuintXX` so both operands share a type and zone.
* **Decryption errors** mean a result was read before it existed, or the wrong entry point was used.

## Troubleshooting tips

When encountering errors:

1. **Check error messages carefully**: The error name and description provide clues about what went wrong
2. **Verify input types**: Ensure encrypted values match expected types
3. **Check permissions**: Verify that `FHE.allowThis()` or `FHE.allowSender()` have been called where necessary
4. **Review component versions**: Ensure all CoFHE components are up to date
5. **Test in mock environment**: Use the mock environment to debug issues without network delays

<Tip>
  Many errors can be prevented by following [best practices](/fhe-library/introduction/best-practices) and ensuring proper access control management.
</Tip>

## Next steps

* Use the [CoFHE Errors Package](/fhe-library/reference/cofhe-errors) to decode error selectors
* View the complete [Error Reference](/fhe-library/reference/cofhe-errors-reference)
* Review the [Compatibility](/get-started/introduction/compatibility) page for version requirements
* Learn about [access control](/fhe-library/core-concepts/access-control) to prevent authorization errors
* Check [best practices](/fhe-library/introduction/best-practices) for secure FHE development