I know Ethereum had several updates over the last couple months and suffered an unintentional fork. Before all that started, I was using an older version of Mist (maybe ~0.8.6? Could have been older) and Geth, and decided I'd just sit it out until things stabilized. A few weeks ago, I fired up my Ethereum and tried to sync, but started getting Geth errors implying "bad" or "unexpected" data from peers. I figured I must have pulled down some of the invalid fork, and hoped a newer version would automatically fix things. Today I upgraded to the latest Mist 0.8.8 and Geth 1.5.5. And I'm getting errors like this:
xxx415 eth/downloader/queue.go:894] Peer xxxxxxxxxx73ab1a: header #xxx5691 [xxxxbce1.] broke chain ancestry
xxx229 eth/downloader/queue.go:894] Peer xxxxxxxxxx73ab1a: header #xxx5996 [xxxx6f63.] broke chain ancestry
xxx162 eth/downloader/queue.go:894] Peer xxxxxxxxxx73ab1a: header #xxx2349 [xxxxbfc1.] broke chain ancestry
xxx444 eth/downloader/queue.go:894] Peer xxxxxxxxxx73ab1a: header #xxx9331 [xxxxc2df.] broke chain ancestry
xxx663 eth/downloader/queue.go:894] Peer xxxxxxxxxx73ab1a: header #xxx4080 [xxxx51ac.] broke chain ancestry
xxx557 eth/downloader/queue.go:894] Peer xxxxxxxxxx73ab1a: header #xxx4418 [xxxx9349.] broke chain ancestry
Note I redacted some of those ID's. I left it for about 15 minutes and saw zero progress downloading blocks.
What should I do to recover? Do I need to blow away everything except my private keys, and resync from scratch?
Edit: I'm now seeing messages about db_upgrade.go "Converting nnnnn blocks"
