What does this error message means: "Your bid amount is too high. You cannot bid more than 100 times than the current bid amount. "

Yahoo Japan Auctions system won't allow you bid more than 100 times than the current bid.
Example:
If current bid amount is 500yen, you can bid 49,999yen but you cannot bid 50,000yen or more.

In case you want to bid an amount more than 100 times than the current bid, you have to do this in two steps.
Example:
The current bid amount is 500yen and you want to place 70,000yen.
Place an amount smaller than 50,000yen first (10,000yen, 20,000yenetc.) and once it's submitted, then you can place 70,000yen.