Errors

Exhaustive list of custom errors, selectors, and the conditions that trigger them. Selectors are the 4-byte keccak256 hash of the error signature — computed with cast sig "ErrorName(types...)". Enum parameters encode as their underlying uint8. Note: several error names are reused across files with different parameters (or none), which changes the selector. PolicyNotFound() (IPolicyRegistry) and PolicyNotFound(uint64) (IB20) are unrelated errors with different selectors, as are Unauthorized() (IB20 / IPolicyRegistry) and Unauthorized(address) (IActivationRegistry). Conversely, LengthMismatch(uint256,uint256) shares one selector across IB20Asset and B20FactoryLib — they’re independently declared but identical in signature.

`IB20`

Error	Selector	Thrown when
`NonPayable()`	`0x6fb1b0e9`	ETH was attached to a call targeting a nonpayable token selector.
`AccessControlUnauthorizedAccount(address account, bytes32 neededRole)`	`0xe2517d3f`	`account` does not hold `neededRole`.
`Unauthorized()`	`0x82b42900`	Caller failed a positional authorization check that isn’t expressible as “missing role X”.
`ContractPaused(uint8 feature)`	`0xfd8c4245`	The `PausableFeature` covering the operation is currently paused.
`InsufficientAllowance(address spender, uint256 allowance, uint256 needed)`	`0x192b9e4e`	`spender`’s allowance is less than `needed` for the requested `transferFrom`.
`InsufficientBalance(address sender, uint256 balance, uint256 needed)`	`0xdb42144d`	`sender`’s balance is less than `needed` for the requested transfer or burn.
`InvalidSender(address sender)`	`0x4c14f64c`	The transfer’s source address is invalid (typically `address(0)`).
`InvalidReceiver(address receiver)`	`0x9cfea583`	The transfer’s destination address is invalid (`address(0)`, or any B20-prefix address).
`InvalidApprover(address approver)`	`0x8bc146c4`	The approval’s `owner` address is invalid (typically `address(0)`).
`InvalidSpender(address spender)`	`0x4e15efda`	The approval’s `spender` address is invalid (typically `address(0)`).
`InvalidAmount()`	`0x2c5211c6`	An amount argument was zero where a non-zero value is required. Not used for ERC-20 amount arguments.
`EmptyFeatureSet()`	`0x4861ff45`	An empty array was passed to a function that requires at least one element.
`InvalidSupplyCap(uint256 currentSupply, uint256 proposedCap)`	`0x0a3780ce`	The proposed supply cap is below the current `totalSupply`, or above `type(uint128).max`.
`SupplyCapExceeded(uint256 cap, uint256 attempted)`	`0x4b344b11`	The mint would push `totalSupply` past the configured cap.
`PolicyForbids(bytes32 policyScope, uint64 policyId)`	`0xa43fec12`	A policy slot denied the operation.
`PolicyNotFound(uint64 policyId)`	`0xcccad523`	The provided policy ID does not exist in the policy registry.
`UnsupportedPolicyType(bytes32 policyScope)`	`0xcdd98a4a`	`policyScope` is not a slot this token (or its variant) supports.
`AccountNotSeizable(address account)`	`0x91dbbc8d`	`seizeWithMemo` was called against a `from` that is not seizable under `SEIZE_HOLDER_POLICY`.
`AccountNotBlocked(address account)`	`0x64a5cb46`	The deprecated `burnBlocked` was called against a `from` that is currently authorized under `TRANSFER_SENDER_POLICY` (i.e. not blocked).
`ExpiredSignature(uint256 deadline)`	`0xbd2a913c`	An EIP-2612 `permit` was submitted with a `deadline` strictly less than `block.timestamp`.
`InvalidSigner(address signer, address owner)`	`0x7ba5ffb5`	ECDSA recovery on an EIP-2612 `permit` returned `signer`, which does not match the claimed `owner`.
`LastAdminCannotRenounce()`	`0x361513e7`	`renounceRole(DEFAULT_ADMIN_ROLE, ...)` was called by the sole remaining admin.
`NotSoleAdmin()`	`0x2a98e73b`	`renounceLastAdmin()` was called when other accounts also hold `DEFAULT_ADMIN_ROLE`.
`AccessControlBadConfirmation()`	`0x6697b232`	The `callerConfirmation` argument to `renounceRole` was not `msg.sender`.

`IB20Asset`

Error	Selector	Thrown when
`AnnouncementIdAlreadyUsed(string id)`	`0xd10b3c9e`	`announce` was called with an `id` that has already been consumed.
`InvalidMetadataKey()`	`0x86ea3abb`	`updateExtraMetadata` was called with an empty `key`.
`InvalidMultiplier()`	`0x6f12f3dc`	A multiplier setter (`updateUIMultiplier` or the deprecated `updateMultiplier`) was called with a multiplier of zero or above the `type(uint128).max` overflow guard.
`EffectiveAtInPast(uint256 effectiveAt)`	`0x14119cf6`	`updateUIMultiplier` was called with an `effectiveAt` that is not in the future.
`EffectiveAtTooFar(uint256 effectiveAt)`	`0x1ce214fa`	`updateUIMultiplier` was called with an `effectiveAt` above `type(uint64).max`.
`UIMultiplierUpdateExists(uint256 effectiveAt)`	`0x4481a68e`	`updateUIMultiplier` was called while a live pending update already exists.
`UIMultiplierUpdateDoesNotExist()`	`0xa7d6a5ca`	`cancelUIMultiplierUpdate` was called when there is no live pending update.
`LengthMismatch(uint256 leftLen, uint256 rightLen)`	`0xab8b67c6`	A batched function was called with parallel arrays of differing lengths.
`EmptyBatch()`	`0xc2e5347d`	A batched function was called with empty arrays.
`AnnouncementInProgress()`	`0x5c5f0829`	An inner call dispatched by `announce` tried to re-invoke `announce`.
`InternalCallMalformed(bytes call)`	`0x4e2f143e`	An inner call dispatched by `announce` was shorter than four bytes.
`InternalCallFailed(bytes call)`	`0xb288a127`	An inner call dispatched by `announce` reverted with an ordinary revert (reason not bubbled).

`IB20Factory`

Error	Selector	Thrown when
`NonPayable()`	`0x6fb1b0e9`	ETH was attached to a call targeting a nonpayable factory selector.
`TokenAlreadyExists(address token)`	`0x15ef3a57`	A token already exists at the deterministic address derived from `(variant, msg.sender, salt)`.
`InvalidVariant()`	`0xf10e8e43`	`variant` is not a recognized `B20Variant`.
`UnsupportedVersion(uint8 version, uint8 variant)`	`0xc0d8b4e0`	The leading `version` byte in `params` does not match any known encoding for the requested variant.
`MissingRequiredField(string field)`	`0x4a43ae87`	A required string argument was the empty string.
`InvalidCurrency(string code)`	`0x997c1de8`	The stablecoin `currency` was non-empty but contained a non-`A`-`Z` byte.
`InvalidDecimals(uint8 decimals)`	`0xca950391`	The asset `decimals` was outside `[B20Constants.MIN_ASSET_DECIMALS, B20Constants.MAX_ASSET_DECIMALS]`.
`InitCallFailed(uint256 index)`	`0x4eae0860`	One of the `initCalls` reverted with no bubbled reason.

`IPolicyRegistry`

Error	Selector	Thrown when
`NonPayable()`	`0x6fb1b0e9`	ETH was attached to a call targeting a nonpayable policy registry selector.
`Unauthorized()`	`0x82b42900`	Caller is not the admin required by the attempted operation.
`PolicyNotFound()`	`0x720caa4f`	The referenced policy ID does not exist.
`IncompatiblePolicyType()`	`0xf1011ef5`	The operation is incompatible with the policy’s type.
`ZeroAddress()`	`0xd92e233d`	A required address argument was the zero address.
`BatchSizeTooLarge(uint256 maxBatchSize)`	`0x083e2f67`	A membership batch exceeded the registry limit.
`NoPendingAdmin()`	`0xb4539afa`	`finalizeUpdateAdmin` was called with no pending admin staged.
`ChildPoliciesOutsideOfRange()`	`0x697ec868`	A composite policy was created or updated with a child-policy count outside `[MIN_COMPOSITE_CHILD_POLICIES, MAX_COMPOSITE_CHILD_POLICIES]`.
`InvalidChildPolicy(uint64 childPolicyId)`	`0x46508ef6`	A child policy is not an existing simple (ALLOWLIST/BLOCKLIST) policy.

`IActivationRegistry`

Error	Selector	Thrown when
`Unauthorized(address caller)`	`0x8e4a23d6`	Caller is not the activation admin.
`AlreadyActivated(bytes32 feature)`	`0x866b0041`	`activate` was called on a feature that is already activated.
`FeatureNotActivated(bytes32 feature)`	`0xb9b2a425`	`checkActivated` was called on an inactive feature, or `deactivate` was called on a feature that is already inactive.
`DelegateCallNotAllowed()`	`0x0d89438e`	The precompile was invoked via `DELEGATECALL` or `CALLCODE`.
`StaticCallNotAllowed()`	`0xbeaba5b7`	A state-mutating entry point was invoked from a `STATICCALL` frame.

`B20FactoryLib`

Error	Selector	Thrown when
`LengthMismatch(uint256 leftLen, uint256 rightLen)`	`0xab8b67c6`	Two parallel arrays passed to a `build*` helper had different lengths.

Specifications

Reference

Node Operators

Security

`IB20`

`IB20Asset`

`IB20Factory`

`IPolicyRegistry`

`IActivationRegistry`

`B20FactoryLib`

​IB20

​IB20Asset

​IB20Factory

​IPolicyRegistry

​IActivationRegistry

​B20FactoryLib

`IB20`

`IB20Asset`

`IB20Factory`

`IPolicyRegistry`

`IActivationRegistry`

`B20FactoryLib`