It also should be possible to just sync up with the correct nodes if you add these nodes to your solaris.conf

80.209.234.157:60020
80.209.227.8:60020
45.77.151.203:60020


IF THAT DOESN'T WORK, DO ACTIONS BELOW:

You can re-sync your wallet (will required to download the blockchain again) by following these steps:

1. Open solaris folder in app data (%appdata%/solaris)
2. Delete everything EXCLUDING wallet.dat (you should keep a back-up of this file anyway) , solaris.conf and masternodes.conf
3. Restart/Open wallet and let it Sync again.

I repeat, DO NOT DELETE wallet.dat, solaris.conf and masternodes.conf