Bitcoin core "bad-txns-in-belowout" Using bitcoin-cli decoderawtransaction, i got the txid of the only one vin, and the value of two vout are set at 0.015 BTC. Then, using bitcoin-cli gettransaction, i got negative value of amount and fee. How could the transaction have negative value of amount and fee ? Could this be the reason of that error "bad-txns-in-belowout"?


./bitcoin-cli -regtest decoderawtransaction "hexvalue"
{
  "txid": "35d2e765217d71db34fd0cd1cf52f419fc525069ac87ed9f413b194851c70849",
  "hash": "35d2e765217d71db34fd0cd1cf52f419fc525069ac87ed9f413b194851c70849",
  "version": 1,
  "size": 338,
  "vsize": 338,
  "locktime": 0,
  "vin": [
    {
      "txid": "2146415931a60db99ebf60849e2874dd67d37f870249a1ff06adcc6b8244155b",
      "vout": 0,
''' 
    }
  "vout": [
    {
      "value": 0.01500000,
      "n": 0,
      "scriptPubKey": {
        "asm": "OP_DUP OP_HASH160 dd100be7d9aea5721158ebde6d6a1fd8fff93bb1 OP_EQUALVERIFY OP_CHECKSIG",
        "hex": "76a914dd100be7d9aea5721158ebde6d6a1fd8fff93bb188ac",
        "reqSigs": 1,
        "type": "pubkeyhash",
        "addresses": [
          "n1fprNxRhWrpkJ34A4cNsSZbHsnzhob2KL"
        ]
      }
    },
    {
      "value": 0.01500000,
      "n": 1,
...
    }
}

./bitcoin-cli -regtest gettransaction 2146415931a60db99ebf60849e2874dd67d37f870249a1ff06adcc6b8244155b
{
  "amount": -0.08000000,
  "fee": -0.00100000,
  "confirmations": 0,
  "trusted": true,
  "txid": "2146415931a60db99ebf60849e2874dd67d37f870249a1ff06adcc6b8244155b",
...
}
How could the transaction have negative value of amount and fee ? Could this be the reason of that error "bad-txns-in-belowout"?


No, it is not. The negatives you see are normal; the values are actually positive, but because you are sending money away from your wallet, they will display as negative relative to your wallet.

That error means that the value of the inputs is less than the value of the outputs. You need to check that output 0 of 2146415931a60db99ebf60849e2874dd67d37f870249a1ff06adcc6b8244155b actually has the value that you want to spend.