Consensus received an invalid block: block does not meet target

[tsangsir]

1. siad outputs lots of messages like

Received an invalid block set.
Received an invalid block set.
Received an invalid block set.

2. consensus.log contains lots of message about invalid blocks

2018/02/13 15:14:54.374267 accept.go:290: accept: finished block processing loop
2018/02/13 15:14:54.451635 accept.go:299: Consensus received an invalid block: block does not meet target
2018/02/13 15:15:50.136145 accept.go:245: accept: starting block processing loop (10 blocks, height 140473)
2018/02/13 15:15:50.338401 accept.go:290: accept: finished block processing loop
2018/02/13 15:15:50.381883 accept.go:299: Consensus received an invalid block: block does not meet target

3. Consensus height stayed at 140473, matching the height of the invalid block, even it claims to be in-sync. (As of this post, the height should be 141573)

$ siac consensus
Synced: Yes
Block:      0000000000000001fa3bd3b47483bc833f5206e4631459686327fd76492ad323
Height:     140473
Target:     [0 0 0 0 0 0 0 2 188 225 133 56 249 210 248 122 129 123 139 116 204 113 190 71 125 197 78 158 74 182 0 140]
Difficulty: 6737758468891502720

So it seems the consensus DB is corrupted.

My questions:

1. How to fix it?
2. Will this cause losses in collateral of my hosting contracts? "siac host" says "Host appears to be working.", but no change in used storage for some time.

[tsangsir]

I ended up downloading the blockchain from https://consensus.siahub.info ... It took around 12 hours to catch up the consensus (upon download, it's around 7 hour old).
Then errors appeared in transactionpool.log. So I removed the directory and let it regenerate everything. I did not know how it take but after I wake up, everything was up and running.
I checked host.log and found lots of error too. But it repaired itself... Perhaps the transaction pool could do so too.