Warning: error reading wallet.dat All keys read correctly,but transaction data or address book entries might be missing or incorrect.
Try -rescan or -reindex, faster fix than deleteting and redownloading. Database coreupts when wallet has unexpected shutdown. But the wallet crashes don't happen that often to me, maybe 5 times since the coin launch. To run commands i mentioned above, go to folder where wallet executable is located. Shift right click folder background and click open command or powershell here. In console window type name of wallet executable and - rescan or - reindex behind it. (make sure wallet is not running)