Transaction
SimulationFailed
“Transaction simulation failed: Error processing Instruction N: ...”
The RPC node simulated your transaction before sending it and an instruction failed. The text after the colon tells you which instruction and why.
Common causes
- Any program error in instruction N. Look for
custom program error: 0x…or a named instruction error at the end of the message. - Stale account state between building and simulating the transaction.
How to fix it
- Paste the full error into the decoder at the top of this site: it extracts the code and links to the explanation.
- Inspect the simulation logs (
simulateTransactionreturnslogs) forProgram log:lines just before the failure.