LTC address from LTC core invalid?


I installed Litecoin core, it started downloading blocks, so I press “Hide” and generated Wallet for receiving LTCs. I sent this address to my client and closed LiteCoin core.

After he sent me 0.5 LTC I opened Litecoin core again and this time I let the wallet to download everything. After this I have 0 LTCs on my account and the address I have generated is not anymore in the list - it it complete empty.

And unfortunately I didn’t backup my wallet.

Thank you for any advice.