ERROR main: CheckTxShieldedInputs(): shielded requirements not met

Hi, since upgrading to v5.0.0, my debug.log is full of this error:

2022-07-08T10:38:05.453846Z INFO ProcessNewBlock: main: UpdateTip: new best hash=00000000015f92440425424c94037b0dd90e11d6f1c60156fc84ddf8fdfab833 height=1730303 bits=469879056 log2_work=59.283307 tx=11019187 date=2022-07-08 10:37:45 progress=1.000000 cache=2.8MiB(554tx)
2022-07-08T10:38:05.466000Z ERROR main: CheckTxShieldedInputs(): shielded requirements not met txid=2f7090768e4145f684fcd439da3d3b91cdacf29048d660d59ccf2f24569d7302 reason=bad-txns-sapling-duplicate-nullifier
2022-07-08T10:38:05.481421Z ERROR main: CheckTxShieldedInputs(): shielded requirements not met txid=a88d09f0f7aa81d06cd120f25ba55c2bca9de62b39ce6b324b2e13641d488e01 reason=bad-txns-sapling-duplicate-nullifier
2022-07-08T10:38:05.499278Z ERROR main: CheckTxShieldedInputs(): shielded requirements not met txid=837d6d5c2fd9dc873a796115f880539d739ffdca225409833f7b64e7ce13dc2c reason=bad-txns-sapling-duplicate-nullifier
...

I’d rather not -reindex, is it necessary?

This is not an error with your node, it is indicating that some transaction in the mempool is a double-spend (which is an error to include in a block, but that’s intentionally detected and rejected). We’ve actually turned down the log level on these messages for the upcoming 5.1.0 release so they won’t show as errors anymore.

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Oh, interesting, thanks. Why so many dbl spends? Surely not intentional, is it a quirk of some ZEC app, maybe a game?

Likely just the huge number of shielded transactions being submitted to the network and filling blocks for the past few weeks, indicating that whoever is creating those transactions is not doing so carefully.

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Bizarre! Sounds like spam. Still, could be explained by poorly designed wallet architecture - for an exchange maybe, so much activity though.

Anyway, thanks for the tech support - much appreciated.

I’ve now upgraded to v5.1.0 and indeed those errors aren’t coming through in the default level of logging. Thanks!

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