A few days ago, chess players using 32-bit devices found themselves locked out of chess.com. From the forum:

The reason that some iOS devices are unable to connect to live chess games is because of a limit in 32bit devices which cannot handle gameIDs above 2,147,483,647. So, literally, once we hit more than 2 billion games, older iOS devices fail to interpret that number! This was obviously an unforeseen bug that was nearly impossible to anticipate and we apologize for the frustration. We are currently working on a fix and should have it resolved within 48 hours.

This sort of thing comes up in computing periodically. In this case, if I’m reading this correctly, the variable used to hold the gameID was not big enough to handle chess.com’s growth. It is not clear if this problem is limited to iOS devices.

Could the developers have seen this coming? Probably. And even if they didn’t anticipate their success, they might have seen the gameID approaching this limit, made the change earlier.