2019-06-27 22:56:14 ERROR: ReadBlockFromDisk: Errors in block header at CBlockDiskPos(nFile=16, nPos=6557320)
It looks like your local chain got somehow corrupted (maybe the Qt client shut down too early or the computer lost power during sync).
The best course of action is to re-build the blockchain from the beginning. You’ll have to back up your wallet file and make sure it’s safe, then delete the blockchain directories and data files from your FLO datadir.
Some more information about these types of errors can be found here: https://github.com/bitcoin/bitcoin/issues/8523
Deleting files is extremely dangerous and you must make sure your wallet is backed up properly before proceeding.