Troubleshooting

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Common Errors

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NotInitialized

error NotInitialized();

• Calling resolve(), flag(), reset(), pause(), or getExpectedPayouts() on a question that hasn’t been initialized
• The questionID doesn’t exist in the adapter

• Verify the questionID is correct
• Check that initialize() was called successfully
• Query isInitialized(questionID) to confirm state

bool initialized = adapter.isInitialized(questionID);
if (!initialized) {
    // Question doesn't exist
}

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Initialized

error Initialized();

• Attempting to call initialize() with ancillary data that produces an existing questionID
• The questionID is derived from keccak256(ancillaryData), so duplicate ancillary data causes this error

• Use unique ancillary data for each question
• Remember that ancillary data includes the creator address appended by the contract
• If you need to re-ask a question, use different ancillary data (e.g., add a nonce or timestamp)

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Resolved

error Resolved();

• Calling resolve(), flag(), reset(), or pause() on an already resolved question
• Question has resolved = true in storage

• Check resolution status before attempting operations
• Resolved questions are immutable and cannot be modified

QuestionData memory question = adapter.getQuestion(questionID);
if (question.resolved) {
    // Already resolved, cannot modify
}

​

Paused

error Paused();

• Calling resolve() or getExpectedPayouts() on a paused question
• Questions are paused when pause() or flag() is called

• Wait for an admin to call unpause() or unflag()
• Check pause status before attempting resolution

QuestionData memory question = adapter.getQuestion(questionID);
if (question.paused) {
    // Paused, resolution blocked
}

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Flagged

error Flagged();

• Calling flag() on an already flagged question
• Calling getExpectedPayouts() on a flagged question

• Check flagged status using isFlagged(questionID)
• Wait for admin to resolve manually or unflag

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NotFlagged

error NotFlagged();

• Calling unflag() on a question that isn’t flagged

• Verify the question is actually flagged before attempting to unflag

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NotReadyToResolve

error NotReadyToResolve();

• Calling resolve() when the Optimistic Oracle hasn’t settled the price yet
• The OO liveness period hasn’t expired
• No proposer has submitted a price

• Check ready(questionID) before calling resolve()
• Wait for the liveness period to pass after a proposal
• Ensure a price has been proposed on the OO

if (!adapter.ready(questionID)) {
    // Not ready: either no price, paused, or already resolved
}

function _ready(QuestionData storage questionData) internal view returns (bool) {
    if (!_isInitialized(questionData)) return false;
    if (questionData.paused) return false;
    if (questionData.resolved) return false;
    return _hasPrice(questionData);
}

​

PriceNotAvailable

error PriceNotAvailable();

• Calling getExpectedPayouts() when the OO hasn’t settled a price
• Similar to NotReadyToResolve but for read-only operations

• Wait for the OO to settle the price
• Check ready(questionID) first

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UnsupportedToken

error UnsupportedToken();

• Calling initialize() with a rewardToken not on the UMA collateral whitelist
• The token address is not approved by UMA governance

• Use a whitelisted token (typically USDC, WETH, or other major tokens)
• Check the UMA collateral whitelist contract
• Query whitelist status:

address token = 0x...; // Your reward token
bool isWhitelisted = collateralWhitelist.isOnWhitelist(token);

• USDC: 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 (Ethereum)
• Check UMA documentation for network-specific addresses

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InvalidAncillaryData

error InvalidAncillaryData();

• Ancillary data is empty (length = 0)
• Ancillary data exceeds maximum length (8139 bytes after appending creator)

• Provide non-empty ancillary data
• Keep ancillary data under ~8100 bytes to account for creator address append
• The contract appends the creator address, so total length = ancillaryData.length + creator_address_bytes

uint256 public constant MAX_ANCILLARY_DATA = 8139;

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NotOptimisticOracle

error NotOptimisticOracle();

• An address other than the Optimistic Oracle calls priceDisputed() callback
• This is a security check to prevent unauthorized resets

• This error shouldn’t occur in normal operation
• If you see this, investigate for potential attack attempts
• Only the OO contract should call the dispute callback

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InvalidOOPrice

error InvalidOOPrice();

• The Optimistic Oracle returns a price that isn’t 0, 0.5 ether, or 1 ether
• This indicates an invalid YES_OR_NO_QUERY response

• 0 = NO
• 0.5 ether = UNKNOWN/TIE
• 1 ether = YES

• This shouldn’t happen with correct OO setup
• If it occurs, flag the question for manual resolution
• Investigate the OO proposal and dispute process

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InvalidPayouts

error InvalidPayouts();

• Admin calls resolveManually() with an invalid payout array
• Payout array doesn’t pass validation (wrong length or invalid values)

• Must be length 2: [YES_payout, NO_payout]
• Valid combinations: [0, 1], [1, 0], or [1, 1]

• Ensure payout array has exactly 2 elements
• Use only 0 or 1 as payout values
• Follow the pattern: [YES_outcome, NO_outcome]

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SafetyPeriodNotPassed

error SafetyPeriodNotPassed();

• Admin calls resolveManually() before the safety period (1 hour) has elapsed
• The safety period starts when flag() is called

• Wait for 1 hour after flagging before manually resolving
• Check manualResolutionTimestamp in the question data

uint256 public constant SAFETY_PERIOD = 1 hours;

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SafetyPeriodPassed

error SafetyPeriodPassed();

• Admin calls unflag() after the safety period has passed
• Once the safety period expires, the question must be manually resolved

• Unflag questions within 1 hour of flagging, or
• Proceed with manual resolution using resolveManually()

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Debugging Tips

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1. Check Question State

QuestionData memory question = adapter.getQuestion(questionID);

console.log("Request Timestamp:", question.requestTimestamp);
console.log("Resolved:", question.resolved);
console.log("Paused:", question.paused);
console.log("Reset:", question.reset);
console.log("Refund:", question.refund);
console.log("Manual Resolution Time:", question.manualResolutionTimestamp);

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2. Verify Optimistic Oracle State

IOptimisticOracleV2.Request memory ooRequest = optimisticOracle.getRequest(
    address(adapter),
    YES_OR_NO_IDENTIFIER,
    question.requestTimestamp,
    question.ancillaryData
);

console.log("Proposed:", ooRequest.proposedPrice);
console.log("Resolved:", ooRequest.resolved);
console.log("Expiration Time:", ooRequest.expirationTime);

​

3. Monitor Event Logs

const adapter = new ethers.Contract(address, abi, provider);

// Log all events
adapter.on('*', (event) => {
  console.log('Event emitted:', event);
});

// Specific debugging listeners
adapter.on('QuestionReset', (questionID) => {
  console.warn('Question reset - possible dispute or ignore price');
});

adapter.on('QuestionFlagged', (questionID) => {
  console.warn('Question flagged for manual resolution');
});

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4. Test Transaction Before Sending

try {
  await adapter.callStatic.resolve(questionID);
  console.log('Resolution will succeed');
} catch (error) {
  console.error('Resolution will fail:', error.reason);
}

​

5. Check Token Approvals

IERC20 token = IERC20(rewardToken);
uint256 allowance = token.allowance(msg.sender, address(adapter));
uint256 balance = token.balanceOf(msg.sender);

require(allowance >= reward, "Insufficient allowance");
require(balance >= reward, "Insufficient balance");

​

6. Decode Ancillary Data

const ancillaryData = question.ancillaryData;
const decodedData = ethers.utils.toUtf8String(ancillaryData);
console.log('Ancillary data:', decodedData);

​

Common Scenarios

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Question Won’t Resolve

1. ✅ Check ready(questionID) returns true
2. ✅ Verify question is not paused: question.paused == false
3. ✅ Confirm OO has price: optimisticOracle.hasPrice(...)
4. ✅ Ensure liveness period has passed
5. ✅ Check question isn’t already resolved: question.resolved == false

const isReady = await adapter.ready(questionID);
const question = await adapter.getQuestion(questionID);

console.log('Ready:', isReady);
console.log('Paused:', question.paused);
console.log('Resolved:', question.resolved);

if (!isReady) {
  // Check OO
  const hasPrice = await optimisticOracle.hasPrice(
    adapter.address,
    YES_OR_NO_IDENTIFIER,
    question.requestTimestamp,
    question.ancillaryData
  );
  console.log('OO has price:', hasPrice);
}

​

Question Was Reset Unexpectedly

1. Dispute occurred - Someone disputed the proposed price
   • Check for priceDisputed callback in OO logs
   • Review dispute details on UMA voter dashboard
2. Ignore price returned - OO returned type(int256).min
   • Indicates the question should be ignored/skipped
   • Question will reset and request a new price
3. Admin called reset() - Manual failsafe invocation
   • Check for QuestionReset event with admin as transaction sender

const resetEvents = await adapter.queryFilter(
  adapter.filters.QuestionReset(questionID)
);

resetEvents.forEach(event => {
  console.log('Reset at block:', event.blockNumber);
  console.log('Transaction:', event.transactionHash);
});

​

Manual Resolution Required

• Admin has called flag(questionID)
• manualResolutionTimestamp is set
• Question is paused

1. Wait for safety period (1 hour from flagging)
2. Determine correct outcome off-chain
3. Call resolveManually(questionID, payouts)

// Resolve as YES
uint256[] memory payouts = new uint256[](2);
payouts[0] = 1; // YES
payouts[1] = 0; // NO

adapter.resolveManually(questionID, payouts);

​

Token Transfer Failures

1. Insufficient allowance - Approve the adapter as spender
   await rewardToken.approve(adapter.address, reward);
   
2. Insufficient balance - Ensure creator has enough tokens
   const balance = await rewardToken.balanceOf(creator);
   console.log('Balance:', balance.toString());
   
3. Token not whitelisted - Use a UMA-approved token
   const isWhitelisted = await collateralWhitelist.isOnWhitelist(tokenAddress);
   

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Multiple Questions with Same Data

• Even with the same question text, different creators get different questionIDs
• If the same creator needs to ask the same question twice, add a nonce:
  const ancillaryData = ethers.utils.toUtf8Bytes(
    `Q: Will X happen? Nonce: ${Date.now()}`
  );
  

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Gas Optimization Issues

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High Gas Costs on Initialize

• Large ancillary data (approaching 8139 byte limit)
• First-time token approval requires additional gas
• CTF condition preparation

• Keep ancillary data concise (reference external data via hash/URL)
• Pre-approve tokens in separate transaction
• Batch multiple initializations if possible

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Failed Transaction Due to Gas Limit

const gasEstimate = await adapter.estimateGas.resolve(questionID);
const tx = await adapter.resolve(questionID, {
  gasLimit: gasEstimate.mul(120).div(100) // 20% buffer
});

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Getting Help

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Diagnostic Information to Collect

1. Question ID and transaction hash
2. Question state from getQuestion()
3. Event logs for the question
4. OO request state from optimisticOracle.getRequest()
5. Network and block number
6. Error message or revert reason

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Useful View Functions

// Check all question parameters
adapter.getQuestion(questionID)

// Check specific states
adapter.isInitialized(questionID)
adapter.isFlagged(questionID)
adapter.ready(questionID)

// Get expected outcome (if available)
adapter.getExpectedPayouts(questionID)

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See Also

• Monitoring Events - Event tracking and interpretation
• Market States - State transitions and flow
• Errors - Complete error catalog