I'm using the btc.com wallet and I want send 0.001 btc to another address but I'm facing this error:
Uneconomical UTXO requested [type: 1 (limit 6831), txOut.val: 5897, required: 98140]
What does it mean? And how can I resolve it?
This error message seems to indicate that one of the Unspent Transaction Outputs (UTXO) in your wallet has a lower value than the cost of spending it.
In Bitcoin, funds are tracked in the form of distinct transaction outputs. Each time someone gets paid, at least one new transaction output is created. While your wallet may show your funds as a balance, under the hood the balance is actually composed of one or multiple UTXO. To spend a UTXO, an input is added to a transaction. Transaction fees are paid per byte of data. If an input for example used 148 bytes, and the current feerate were 100 satoshi per byte, it would cost 14,800 satoshi to spend a UTXO. If the UTXO's value was 5,897 satoshi, it costs more to spend it than its value— it is uneconomic to spend it.
You may be able to sidestep the error by setting a lower feerate. Note that this will likely cause the transaction to take a long time to confirm.
Altogether, it would be reasonable for your wallet software to filter uneconomic UTXO in the preselection, so you may want to consider reporting this as a UX bug.
Uneconomical UTXO requested [type: 1 (limit 6831), txOut.val: 5897, required: 98140
The output was 5,897 satoshis, but based on the addresses script type (1) the estimated fee incurred by spending this input (based on input_estimated_vsize*feeRate) would be 6,831 satoshsi. At this coin selection step, it was trying to find a coin that would fulfill 98,140 satoshis
The btc.com coin selection algorithm can pick a good UTXO to spend if you have many large UTXOs, but unfortunately, that's the error you get when the only coin available is uneconomical to spend, and the coin selection fails.
The coins value is X, the fee is greater more than X, so spending it wouldn't even contribute to the amount you're paying somebody - it actually costs you money to spend that coin at the selected fee rate.