The DNS checkpoint error is okay. To fix the balance 0 issue follow these steps,

You need to restore your wallet via the seed that was given when the wallet was created.

To do so, create a .bat file and place following commands in it:

for linux: ./stellite-wallet-cli --restore-deterministic-wallet

for win: stellite-wallet-cli.exe --restore-deterministic-wallet

save and start the .bat file.

It will ask you to name your restored wallet, set a new password and type in the seed.

When launching simple wallet afterwards, it will receive blocks and your balance will be shown.