Help with very old wallet.dat file and keys, next steps? recently I found a very old wallet.dat file back from 2011 (I did some mining back then). I was able to run pywallet to export the keys into JSON file, this file includes private keys and all, so i assume it was not encrypted. The structure is as follows, there are bunch of these.

    {
        "addr": "", 
        "compressed": false, 
        "hexsec": "", 
        "private": "", 
        "pubkey": "", 
        "reserve": 1, 
        "sec": "", 
        "secret": ""
    }, 


The question is - what do I do with this now? I want to check if there any coins that I have mined but i have no idea what the next step is.

I have tried copying the value of "private" into Bitcoin Core's console with "importprivkey" but i get "Invalid private key encoding (code -5)"

Thanks for your help!
You don't need to import the keys to see if they have a balance or not. Just copy the content of "addr" and use a Bitcoin blockchain explorer such as https://blockchain.info/ to check if there is any BTC on the address.

And i guess you could just import the wallet.dat on Bitcoin Core directly if there is any BTC on any of your addresses.