Insufficient order size: Exchanges have orders size limits. For example, the minimum order size of BTC/USDT in Binance is 10USDT. Limits can change based on exchanges, pairs or markets. In order to open positions, your bot is checking if the base or safety order size set your DCA bot settings exceed the minimum threshold set by the exchange. If the order size is below that threshold, the bot will not be able to open that order.