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OpenZeppelin 5

0xfb8f41b2: ERC20InsufficientAllowance

error ERC20InsufficientAllowance(address,uint256,uint256)

What it means

A transaction that reverts with the raw data 0xfb8f41b2 hit the custom error ERC20InsufficientAllowance, defined in OpenZeppelin 5. The explorer shows the hex because it does not have the contract's ABI to translate it.

The spender contract is not approved to move this much of the token. The error data carries the spender, its current allowance, and the amount it needed.

How to fix it

Approve the token for the spender, for at least the amount in the transaction, then retry. The most common cause of a first swap or stake failing.

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More OpenZeppelin 5 errors

0x118cdaa7OwnableUnauthorizedAccount
0x1e4fbdf7OwnableInvalidOwner
0xe450d38cERC20InsufficientBalance
0x96c6fd1eERC20InvalidSender

Every selector on this page was computed as the first 4 bytes of keccak256 of the signature shown. A selector identifies a signature exactly; on rare occasions two different signatures share one, so the transaction decoder is always the more precise answer.