Shortly after HF 21 was applied:
an overflow happens in the new downvote pool calculations for large stakeholders. The bug was found and fixed shortly after:
https://github.com/steemit/steem/compare/downvote-overflow-fix
The fix did not required a replay of all blocks and the steem chain could be restarted to produce blocks again.
scotbot
After some node switching (api.steemit.com was still down), scotbot could be restarted and is running again.
beem
I started to work on beem version 0.21.0 which will include the new features on HF 21. beem is a powerful python library for Steem.
I already voted for a proposal
from beem import Steem
stm = Steem()
stm.wallet.unlock("...")
stm.update_proposal_votes([0], True, account="holger80")
I pushed the changes to the master branch here: https://github.com/holgern/beem