Error codes / 0x21
custom program error: 0x21
Custom(33) · 0x21 · used by 3 programs we know
This number has no meaning on its own. Each Solana program numbers its own errors, so 0x21 is CheckedAddOverflow in Raydium AMM V4 but WrongVoucherOwner in Metaplex NFT Packs. The meaning that applies is the one from the program that actually failed: the first Program … failed line in the transaction's logs. That is often not the program you called, but one it invoked, or a guard instruction your wallet added.
Don't guess: paste the transaction
TxWhy reads the logs, finds the program and the exact instruction that raised 0x21, explains it, and rebuilds the transaction when the cause is one it can fix.
What 0x21 means, by program
- CheckedAddOverflowRaydium AMM V4
An arithmetic operation inside the program went out of range. In exchanges this usually means the amount, price or liquidity at that moment produced a number the pool cannot represent, often a trade far larger than the pool can absorb.
- WrongVoucherOwnerMetaplex NFT Packs
Voucher owner mismatch
- PrintingMintAuthorizationAccountMismatchMetaplex Token Metadata
The program raised this named error and published no further explanation.