TAPOS_ERROR: the transaction points to an unknown block
Each TRON transaction names a recent reference block (ref_block_bytes and ref_block_hash). TAPOS_ERROR means the node cannot find that block on its chain: it is too old, or the transaction was built against another network — a Nile testnet transaction sent to mainnet, for example.
Nothing was charged. Rebuild the transaction from a node of the network you are sending to, sign it and broadcast it promptly.
Common causes
| Cause | Fix |
|---|---|
| Built on Nile, sent to mainnet (or the reverse) | Build and send through the same network |
| Built long ago from an old block | Rebuild from the current head block |
| The building node was behind or on a fork | Use a synced node |
TRON network rules as of 2026-10-01.
FAQ
Is this a problem with my funds?
No. It is about how the transaction was built; balances are untouched.