Error initializing database environment /home/user/.SHIELD! To recover, BACKUP THAT DIRECTORY, then remove everything from it except for wallet.dat.
ERROR: CDB() : error Invalid argument (22) opening database environment
It looks like you just need to delete the blockchain and resync, that's all. Do what it tells you: go to ~/.SHIELD , back it up, then delete everything inside it except for your wallet. Then restart the daemon.
Or have you already tried that?