Well, I figure I'd better come in here and voice up. Been reading along ever since the first instance of the "checkpoint is too old" error, and the common resolve seems to be "redownload the [entire f%$#ing] blockchain from one peer". As a coin itself, I can't see this as a solution. For mine, it worked - finally resolved the error just by telling it who to connect to. But that's not the point. Let me go back a few hours and explain what led up to this error.
I wanted to give BitBar a try. The name and the concept were the big sell - a low-quantity currency meant to be a "bigger" Bitcoin. BitBars, Bitcoins, and Litecoins. Seems like a "coin" that could stand up to the test of time, unlike some others that are obviously get-rich-quick schemes for the devs. So, I checked out the website. Horribly disappointed. Front page is just "news", telling users to redownload the blockchain? Gotta be kidding me. Well... I press on. Downloads page said the "latest version is 0.4.1", pointing to a Google Drive download link that only has 0.4.2 and 0.4.3 (was dead the first time I tried it, though - blank page). 0.4.2 is the latest news post - what the hell is 0.4.3? Whatever, I grabbed 0.4.3 - newer is better, I guess.
Extracted it (no installer? Come on... more tedium for the end-user, this clearly isn't a project meant to be used for more than just miners), ran it. It started off showing a low number of blocks remaining to download, but then jumped after a few thousand had gone by... chugged away for a while... then eventually just hung for the next hour or so with several thousand blocks remaining (I think over 20,000). So, frustrated, I closed it and opened it up again.
Then I got the dreaded "checkpoint is too old, contact the devs" error. With a fresh download of the blockchain, with the latest client, starting from pure scratch.
Rule of thumb: your currency is doomed if your mainline client can't get online without editing a config file.
I got it working by adding "connect=84.200.4.218" to the config file and running "bitbar-qt.exe -rescan" - without the "rescan", it would still give the checkpoint error even after previous launches with "-rescan" connecting to a dead peer. The price of BTB is higher than any other currency besides Bitcoin right now, so it's definitely worth getting into - but will it last beyond the "OMG BITCOIN $1,000 EVERYTHING ELSE IS FAIR GAME" bubble? I dunno. I'm trying to give it the benefit of the doubt. But the technical errors and sketchy usability put a lot of doubt in my mind about the long-term stability of the project.
Could the blockchain-download bug be caused by a peer that's sending out that partial fork from earlier? Maybe the Bitbar client isn't making the proper differentiation between the good and bad peers, or failing to recover from being given a bad block? I don't know enough technical details, but it doesn't seem like *anyone* in this thread is giving the "checkpoint too old" error the attention it very clearly deserves... just "tape-over the check engine light, redownload block chain".
All this, and I still have no idea what the "Stake: 0.00" in my wallet is referring to. Like I said... usability problems.