Those “invalid transaction” log lines are not a problem — they’re P2Pool doing its job correctly.

What’s happening: P2Pool shares a mempool view across its sidechain network. When a node receives a block template that references transactions, it validates each one locally. If a transaction has size=0, weight=0, fee=... it means P2Pool received a fee reference but couldn’t find/validate the full transaction in your local mempool. This is a normal race condition between mempool propagation and block template timing.

The Qubic connection: Yes, there was a period in 2025 where Qubic mining was injecting very large numbers of micro-transactions into the Monero mempool (they were using merged mining via a sidechain approach). These often propagated unevenly across the network. Some P2Pool nodes would receive fee data about transactions that hadn’t fully propagated yet → hence the size=0 entries.

What to check:

• Are these lines continuous/persistent, or occasional? Occasional = totally normal.
• Run monerod status — is your node fully synced and connected to enough peers (8+)?
• If you’re seeing thousands per minute, check if your Monero daemon is poorly connected.

Bottom line: these log lines are informational, not errors. Your P2Pool is working correctly.