Research "INFO: read txPrev failed" log messages

[shane-kerr]

As the wallet synchronizes, we see a lot of this error:

received block 1bcb618870813727cac3
ERROR: CheckProofOfStake() : INFO: read txPrev failed
WARNING: ProcessBlock(): check proof-of-stake failed for block 1bcb618870813727cac3011fd11b9efccd52f42e5e83c84b4c24d09bb6930d5b
ERROR: ProcessBlock() failed
ProcessMessage(block, 411 bytes) FAILED

The code claims "yeah it happens", but it seems to me that this must be a bug. We should not have any problem reading any previous information for blocks added years ago, I think.

[EuroCentiem-dev]

ERROR: CheckProofOfStake() : INFO: read txPrev failed
WARNING: ProcessBlock(): check proof-of-stake failed for block 34361c38de958e483b43d1a1b69fb5f321e682b154704c705628784dadb07fd3

34361c38de958e483b43d1a1b69fb5f321e682b154704c705628784dadb07fd3 belongs to height 5,953,641

while current chain is only at 1915123

./mintcoind getinfo
{
"version" : "v2.1.1",
"protocolversion" : 60008,
"walletversion" : 60000,
"balance" : 0.00000000,
"newmint" : 0.00000000,
"stake" : 0.00000000,
"blocks" : 1915123,
"moneysupply" : 22068374898.79887772,
"connections" : 9,
"proxy" : "",
"ip" : "",
"difficulty" : 2.39599867,
"testnet" : false,
"keypoololdest" : 1619628167,
"keypoolsize" : 101,
"paytxfee" : 0.10000000,
"errors" : ""
}

So according to me the error is correct as there the function tries to read a tx from disk but the wallent hasn't catched up yet.