Does anyone know what's wrong with the blockchain?
Transactions appear/disappear randomly, balances are shown wrongly, withdrawal from Polo doesn't work (txid not found), Bittrex wallet under maintenance..

The explorer nodes forked. We will restart them as soon as possible.
Ah, okay.
I'm interested, under what circumstances can this happen?
I guess, for example, when a few nodes don't receive transactions for a while (go offline etc.) and after they're online again, consensus is impaired?
(But wouldn't they just resync then?)