I am having the exact same problem. The first time I had to uninstall/reinstall to get things to work. Copied the same config.js and it started working.
After the bot had made 20-30 successful trades (buying and selling), I edited the config.js to change the trading limit, and now am getting the same error. Bot will sell but will not buy. I am trading on Bittrex. I know this doesn't answer your question, but here's a little more info from my config.js. Bot was trading fine set to 0.01 to test these settings, but will not trade with the current trading limit, that account has around 0.175 btc in it. The bot is currently on round #1500, well past the trading safety time.
This is running gunthy.exe, not using the ui.
"strategies": {
"bb": {
"NAME": "bb",
"TRADING_LIMIT": 0.03,
"PERIOD": 15,
"BUY_LEVEL": 0.6,
"GAIN": 1.5,
"EMA1": 2,
"EMA2": 4,
"HIGH_BB": 25,
"LOW_BB": 25,
"STDV": 2,
"SMAPERIOD": 20,
"PANIC_SELL": false,
"DOUBLE_UP": false,
"DOUBLE_UP_CAP": 1,
"STOP_LIMIT": 60,
"BUY_ENABLED": true,
"MIN_VOLUME_TO_BUY": 0.001,
"MIN_VOLUME_TO_SELL": 0.001,
"TRADES_TIMEOUT": 600
"bot": {
"debug": false,
"BOT_DELAY": 1,
"interval_ticker_update": 25000,
"period_storage_ticker": 2000,
"timeout_buy": 60000,
"timeout_sell": 60000,
"TV_GAIN": 0.6,
"TV_TRADING_LIMIT_BUY": 0.001,
"TV_PYRAMID": false,
"TV_TRADING_LIMIT_SELL": 0.001,
"TV_PROTECTION": false,
"VERBOSE": true,
"WATCH_MODE": false
