Hello bitcoin comunity in need help with an old wallet on a Toshiba tablet. Stuck at synchronisation ... I have some btc in it but i have this problem. The tablet runs Bitcoin core v0.8.7.4-unk-beta on windows 8.1. It has reach about 576412 block till about 51 weeks ago then it stopped synchronising. I encripted the wallet , made a back up ant transfer it on a laptop with the new 0.21.1 version. The transfered amount was sent in 2015 , but when i transfered the wallet.dat it reads 0 btc. I reached 99.1 % of sync on my laptop but it went past that date and didn,t verify that transaction of the incomings btc. The balance stayed 0. I tried searching the addresses manualy on the blockchain , and all results were , this address dont exist. I noticed when i transfered the dat file all original transaction adresses changed completely. And everyone shows either non existant or 0 inputs or outputs. I believe the wallet hide somehow the original addresses and i cant get the corect priv key. I tried dumping the wallet and checking all addresses individualy still returns 0 in every one. I cant use dumpwallet on the tablet because that command is not available in v0.8.7 How can i find the original btc address. But since the tablet is of friend of mine ,he asked me for help.I cant start it synchronising. Im afraid to update it forcecfuly , because i've red you can loose the amount of the wallet. I believe the original version is not installed but copied over , i dont find the btc core in the remove programs tab on windows. All help will be apreciated. I can give adittional info if needed. Sorry for my bad english.
You can try the command
dumpprivkey into the console.
First get all your UTXOs typing the command
listunspent into the console, then you will have all your BTC address with funds, then you can take their private key with the command
dumpprivkey <address>. Once you have it, you can use a light wallet like Electrum and import your private key there, then you will be able to spend your funds.
Keep in mind as your wallet is still syncing, your final balance may not be correct, but if you are sure you have some Bitcoins in that wallet, you should be able to recover them through those steps.