> ## Documentation Index > Fetch the complete documentation index at: https://docs.cdp.coinbase.com/llms.txt > Use this file to discover all available pages before exploring further. # Troubleshooting Common issues and solutions when integrating with Custom Stablecoins swaps. ## Common Errors ### SwapsCannotBePaused **Error:** Transaction reverts with `SwapsCannotBePaused()` **Solution:** Swaps are currently disabled on the contract. Wait for the PAUSE\_ROLE holder to re-enable swaps. ### TokenNotListed **Error:** Transaction reverts with `TokenNotListed(address)` **Solution:** The token address you provided is not listed on the contract. Verify the token address against the [Key Addresses](/custom-stablecoins/conversions/stableswapper-contract/key-addresses) page. ### TokenMustBeSwappable **Error:** Transaction reverts with `TokenMustBeSwappable(address)` **Solution:** The token is listed but currently disabled for swapping. Wait for the PAUSE\_ROLE holder to re-enable the token. ### SlippageExceeded **Error:** Transaction reverts with `SlippageExceeded()` **Solution:** The output amount after fees and decimal normalization is less than your `minAmountOut`. Increase your slippage tolerance or re-read the current `feeBasisPoints()` value and recalculate. ### AmountOutExceedsAvailableLiquidity **Error:** Transaction reverts with `AmountOutExceedsAvailableLiquidity(amountOut, availableLiquidity)` **Solution:** Reduce your swap amount. The contract doesn't have enough output token liquidity (after accounting for reserved amounts) to fulfill the swap. ### AddressNotInAllowlist **Error:** Transaction reverts with `AddressNotInAllowlist(address)` **Solution:** The allowlist feature is enabled and your wallet address is not allowlisted. Contact support to be added. ### CannotSwapSameToken **Error:** Transaction reverts with `CannotSwapSameToken(address)` **Solution:** You specified the same token address for both `tokenIn` and `tokenOut`. Use two different token addresses. ### ERC-20 approval errors **Error:** Transaction reverts during `transferFrom` with no descriptive error **Solution:** You need to approve the Stableswapper contract to spend your input tokens before calling `swap()`. Call `approve()` on the input token contract first: ```typescript theme={null} const token = new ethers.Contract(tokenAddress, ERC20_ABI, signer); await token.approve(STABLESWAPPER_ADDRESS, amountIn); ``` ### Insufficient gas **Error:** Transaction fails with `insufficient funds for gas` **Solution:** You need Base Sepolia ETH for gas fees. Get testnet ETH from [CDP Faucet](/faucets/introduction/quickstart). ## Common Errors ### AccountNotInitialized **Error:** `user_from_token_account` - Account not initialized **Solution:** You need USDC tokens in your wallet. Get devnet USDC from [CDP Faucet](/faucets/introduction/quickstart). The example code includes logic to auto-create the destination token account if needed (`needsAccountCreation`). However, you must have the **input token** (USDC) before swapping. ### Insufficient lamports **Error:** `insufficient lamports` or `insufficient funds for rent` **Solution:** You need more SOL for transaction fees and rent. Get at least 0.05 SOL from [CDP Faucet](/faucets/introduction/quickstart). ### InsufficientLiquidity **Error:** Not enough reserves in the output vault **Solution:** Reduce swap amount or wait for liquidity to be added. ### SlippageExceeded **Error:** Output is less than `min_amount_out` **Solution:** Increase slippage tolerance or re-fetch current fee rate. ### NotWhitelisted **Error:** Transaction signer is not on the whitelist **Solution:** Contact support to be added to the whitelist. *** ## What to read next Helper functions for validation More swap code examples Swap instruction parameters Back to quickstart guide