Hey just to follow up the recent bump: on LoyceV's advice, I spent time in recent days claiming my various BTC forks from a wallet last used in 2014, which means I now own ~0.5 in each of BCH, BSV, BTG and BCHA

 If you can tolerate a few hours of tinking with various wallets, it might be well worth your time to follow the advice contained in this thread. Cheers Loyce!

Update: I've exhausted all possible avenues for any further BTC recovery, of that I'm certain

On LoyceV's advice, I did spend time in recent days claiming my various BTC forks, which means I now own ~0.5 in each of BCH, BSV, BTG and BCHA

For anyone who happens to discover this thread in future, please do follow Loyce's guide here - the original post is a little outdated in terms of which currencies are worth pursuing, but much of it still holds up. If you can tolerate a few hours of tinking with various wallets, it might be well worth your time: https://bitcointalk.org/index.php?topic=2836875.0

You guys are amazingly helpful, thank you. I'll update back in here when I can. Cheers

Yeah. I started looking into how to use PyWallet, but as a total Python noob who hasn't coded in any language in quite a few years, I soon became overwhelmed and discouraged. Is there a straightforward guide to using PyWallet? All the stuff I unearthed online is aimed at a much more Python-savvy audience than someone like me... I would like to invest the time in understanding it, but the nature of my life at present is that I only have an hour here and there, and very few chances to sit at the PC and really put my mind to learning Python.

This is another dumb question perhaps, but how do I actually use that bitcoin-wallet command? It doesn't appear as a command line option in Bitcoin Core itself. Is there a non-GUI way I should be accessing it? I understand it's an offline tool, which I take to mean it doesn't need to sync the blockchain, but I'm clueless as to where to type those commands to interact with it. Any help appreciated.

Belated response: yes, the resynced wallet eventually caught up with my transaction history, and thus reported zero balance. Although interestingly when I loaded the next most recent wallet backup (created a month after the original file mentioned in OP) it began showing an "available balance" exactly the same as the ~0.5BTC sum mentioned earlier in this thread.

Any attempts to perform a test transaction to move a fraction of that amount show the same "0/unconfirmed, not in memory pool" message that I reported earlier in this thread.

So for all intents and purposes, the original wallet has been emptied. I've been running through various other old wallet.dat files backed up more recently than the original file, and they're all empty too. Looks like I'm coming to the end of my historical treasure hunt... although one file (created in late 2015) is showing a message when I try to load it which ends: "...wallet is corrupt. Try using the wallet tool bitcoin-wallet to salvage or restoring a backup."

I've done a little research around that error message and will soon try a few things to investigate further. I doubt it'll result in any further discoveries, but of course I want to be thorough here. Feel free to make any suggestions re that particular error message if you're familiar with it. And thanks for taking the time to read and reply to this random thread.

Definitely no warning shown, and I downloaded the newest version of Bitcoin Core available. Might be an oversight from the developers, or maybe I'm the first idiot to have come across this self-inflicted error!

Blockchain is at 87% synced, with ~37,000 blocks remaining, and it should be done by this time tomorrow. Maybe.

To your other point: the wallet is showing an available balance of zero in the background, while resyncing.

Yes, I'm in the midst of that painful process at the moment. But I've decided to turn off prune mode so that I can more easily check the other old wallets against the blockchain, rather than reindexing every time. (I should have done this in the first place, rather than pruning, but hey, live and learn.)

Yes, that is what I did. And I think you've just unlocked why the ~12BTC amount was showing. We shall see what that same wallet shows once my rescan finishes (in ~5-7 days' time). I suspect it'll be zero.

If that's the case, then I guess the learning from this experience - for anyone who somehow finds this thread in the future - is to not do what I did, lest you get your hopes up that you've discovered non-existent BTC

Strangely, no. After I swept keys to Electrum (while keeping Bitcoin Core open), the only transaction that appeared in my history was a small amount (~0.0001 BTC). Otherwise, the bulk of the "available balance" remained unchanged, ie ~12BTC. So yes, it seems a -rescan in order to see how that affects the amount.

Thanks for this reminder!

Thanks, that is interesting. I've checked a few of the bigger outputs listed under 'listunspent' on Blockchair and they're all at zero.

One other thing that I should have mentioned earlier, perhaps: I am running Bitcoin Core in 'prune mode', ie under Options I've got the checkbox ticked to prune block storage to 2GB rather than the entire ~350GB blockchain

However, my understanding is that using 'prune mode' shouldn't affect the wallet's available balance, as Bitcoin Core still has to go through and verify every historical transaction.

Could it be that the majority of the ~12BTC is caught somewhere in the past, and has actually been spent in 2012-2014 (by me), but for some reason the client thinks it's still available in 2021? How odd...

OK, time to provide an update. Thanks to those who have provided thoughts and feedback. I've done a whole bunch of reading since I created this thread, and finally landed on a course of action, which I'll outline below

First, just to be upfront about my original post: when I loaded my old wallet.dat file, my Bitcoin Core client was showing an available balance of about 12 BTC

This is obviously a life-changing amount of money at this time. But rather than getting carried away with early celebrations, I've been extremely cautious throughout this process as that amount seems extremely high, considering how careful I was with buying/trading/handling BTC in the past. Hence my earlier question about whether that amount is a phantom vestige, or actually able to be used/traded/sold.

So to today: after lots of reading, I decided to use 'dumpwallet' command in Bitcoin Core console to dump all wallet keys, with the intention of sweeping into a new Electrum wallet.

Interestingly, the resulting text file shows ~130 lines for the period between 2012 and 2014, and then ~1000 lines for the period in the last couple of days when I've been poking around with the old wallet.dat file, trying to figure out what to do.

After a bit of massaging, I swept those ~130 lines into my new Electrum wallet, which yielded 0.46BTC. This is not quite the life-changing amount I had seen earlier in my Bitcoin Core available balance, but it's still, as they say, money for nothing in the scheme of things. Nice.

Of that 0.46BTC, I have sent a small text transaction to a local crypto exchange that I've successfully used previously, and if that test is received, hooray. Good to go with whatever I do next, whether cash out or HODL.

Of the ~1000 recent lines generated by 'dumpwallet', I did a test of the first 50 to see if anything could be swept from those wallet keys. No dice. Electrum returns a 'No inputs found' message.

Here's my next question: while sweeping coins from Core to Electrum, I've kept the Core client running, and the available balance of ~12 BTC has stayed the same. Even while my Electrum client is showing a confirmed balance of 0.46 BTC

What do you think is causing Bitcoin Core to show that available balance? Is it "confused" or caught up in a transaction history that... just doesn't exist?

If anyone has any theories on why Bitcoin Core would be showing that available balance of 12 BTC, I'd love to hear it. Genuinely puzzling. As though it's stuck on a different timeline to the one I'm in.

Thanks again for your help. Today is a good day.

Hi all, I'll keep this as simple as possible for brevity's sake - please ask questions if I've left any gaps in explaining my situation, as follows

I bought and traded Bitcoin from approx 2012 to 2014, using Bitcoin-qt as my wallet until I learned about Electrum and began to use it instead

I haven't bought or sold BTC since about 2015, but given the recent price spikes, curiousity has gotten the better of me. I'm fairly sure my old wallets were completely emptied of any BTC, but better safe than stupid, right?

This week I downloaded Bitcoin Core, synced the blockchain to the network (took 5-6 days) and opened the oldest wallet.dat file I had backed up

It contains my transaction history from 2012 to 2014. Even better, the wallet itself seems to contain a non-trivial amount (ie greater than 1BTC), with that amount displayed as "available" and zero BTC under pending. Great!

Yet more joy: when I went to send a test transfer (tiny fraction of BTC) to an Electrum wallet, I was able to remember my years-old password and send the transaction through

Or so I thought... That test transfer has the status of "0/unconfirmed, not in memory pool" within Bitcoin Core. I have done some reading on this (other forum posts across the years) and I'm not clear on why is occurring

Bitcoin Core itself notes in bottom right corner that it's up to date with 669,000+ blocks of transaction history. And the client has 10 active connections to BTC network

So I'm a little confused, and wondering whether the "available" balance amount shown in the wallet is a phantom vestige of many years ago, and not real... or whether there's some other way to salvage what appears to be a functioning wallet?

If you were in my situation, what would you try next?

Thanks in advance