Image Source : Metatrader 5 Terminal
A cryptic error code appearing in your MetaTrader Experts tab can stop an automated strategy right as a setup triggers. These errors often represent the difference between a successful trade and a missed opportunity, especially when you are managing a prop firm challenge where every execution counts. While MetaTrader 4 (MT4) and MetaTrader 5 (MT5) provide robust environments for automation, they require specific configurations to handle incoming webhook signals from a bridge like PineConnector.
Understanding these codes allows you to move from frustration to resolution in seconds. This guide breaks down the most common MetaTrader errors encountered during automated trading and provides actionable steps to fix them.
The Foundation: Start with A Reliable Broker
Before diving into specific error codes, you must recognize that your trading experience begins with selecting the right broker. A reliable broker minimizes platform-related bugs and ensures a smoother transition from testing to live trading. You can find our recommended broker here.
Common MT4 and MT5 "Trade Not Allowed" Errors
The most frequent issues traders face are related to permissions. If your terminal is not configured to allow an Expert Advisor (EA) to place trades, the bridge will fail immediately.
MT4 Error 4109 / MT5 Error 4752 (Trade is Not Allowed)
These errors indicate that automated trading is prohibited by the terminal or the EA settings. 
- The Fix: First, click the "Algo Trading" (MT5) or "AutoTrading" (MT4) button in your top toolbar so it turns green. Second, open the PineConnector EA settings by pressing F7, navigate to the "Common" tab, and ensure "Allow Live Trading" is checked. You should see a smiley face in the top right corner of your chart once this is resolved.
MT4 Error 4017 (DLL Calls are Not Allowed)
PineConnector requires DLL imports to communicate between TradingView webhooks and your MetaTrader terminal.
- The Fix: Open your terminal options (CTRL+O), navigate to the "Expert Advisors" tab, and check "Allow DLL imports". You must also ensure this is enabled within the specific EA properties for PineConnector.
The complete self-hosted installation, including exactly where the DLL and EA files go and both places "Allow DLL imports" needs to be ticked, is in PineConnector's TradingView to MT5 guide. If you would rather not manage that installation yourself, PineConnector Edge hosts a MetaTrader 5 terminal for you, so there is no local EA or DLL install to manage for its supported workflow. Edge currently runs PineConnector's own connector on MetaTrader 5 only; check the Edge guide for its current scope before switching.
Troubleshooting Order Execution Failures
Execution errors usually occur when the instructions sent from TradingView do not match the specific requirements of your broker or the symbol being traded.
MT5 Error 4756 (Trade Request Sending Has Failed)
This is a broad error that often requires checking the "Journal" tab for specific subtypes.
- Unsupported Filling Mode: This occurs when your broker requires a specific execution type (like "Fill or Kill" vs. "Immediate or Cancel"). On a self-hosted terminal, older PineConnector EA versions offer a "Broker Set" setting; switch to "Broker Set B" only if your EA version has it. On PineConnector Edge, send the log detail to PineConnector support and change the hosted Broker Set only when Support asks you to.
- Invalid Volume: This means the trade volume you requested is not supported. Check your broker’s "Symbol Specification" to see the minimum lot size, maximum lot size, and volume step.
- No Prices: This usually happens if the symbol is not enabled in your Market Watch. The EA will typically enable it automatically after the first "no prices" error occurs.
MT4 Error 130 / MT5 "Invalid Stops"
This error triggers when your Stop Loss (SL) or Take Profit (TP) is too close to the current market price, violating the broker's "Stops Level".
- The Fix: Check the "Stops level" in the Symbol List (CTRL+U); remember that 1 pip is defined as 10 points. If you intended to use price targets but your EA is set to "pips" mode, your targets will be placed far too close to entry. We recommend using the pips or percentage Target Type on the EA settings for more consistent results.
Syntax and Symbol Errors
Automation requires perfect communication. A single typo in your TradingView alert message can prevent a trade from ever reaching the market.
MT4 Error 4106 / MT5 Error 4301 (Unknown Symbol)
This error occurs when the symbol indicated in your alert message does not exactly match the symbol name in your MetaTrader Market Watch.
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The Fix: Symbol names are case-sensitive. If your broker uses a suffix (e.g.,
EURUSD.pro), you must include that exact string in your TradingView alert syntax. Sending "eurusd" when the terminal expects "EURUSD" will result in a failure. On PineConnector Edge, the Symbols tab (Portal → Edge → Symbols) lists every symbol your broker offers, with its specification, so you can copy the exact name into your alert instead of retyping it from the terminal (Edge Symbols guide).
MT4 Error 4051 (Invalid Function Parameter Value)
This most commonly happens when a compulsory part of the syntax is missing from your alert.
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The Fix: Ensure every entry command, like buy, sell, buylimit, and sellstop, includes one volume parameter, such as
vol_lots=. Older alerts userisk=instead, and its meaning follows the "Volume Type" in your EA settings. For detailed formatting, refer to the PineConnector Syntax Guide.
Managing Margin and Session Errors
Even with perfect syntax, a trade can fail due to account-level restrictions or market timing.
MT4 Error 134 (Not Enough Money)
This indicates you have insufficient margin to open the position.
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The Fix: Check the Experts tab to see the "required margin" versus your "available margin". If the required margin is higher, you should request a smaller volume in your syntax (for example, a lower
vol_lots=). If an older alert still usesrisk=, confirm the "Volume Type" in the EA settings before reducing it.
MT4 Error 132 (Market is Closed)
This is a straightforward error indicating you are trying to trade outside of the symbol's allowed hours.
- The Fix: Check the trading session hours for the symbol in your terminal's symbol list and ensure your TradingView alerts are only active during those windows.
Infrastructure and Speed Optimization
Sometimes errors aren't about code, but about connection. A "Requote Detected" message is common on demo servers with strict instant-execution rules, regardless of your connection. Hosting your terminal on a VPS keeps it running independently of your own computer, and choosing a VPS location close to your broker's server shortens the network path between the two, alongside your broker's own spread and execution behaviour. ForexVPS (affiliate link) offers Windows VPS plans for MetaTrader. To see which server location is closest to your broker, try a broker latency checker (affiliate link): pick your broker and it lists the lowest-latency location.
If you encounter an error not listed here, such as a "Zero divide" computation error, you should report it to PineConnector support with your EA version and the specific numbers displayed in the brackets.
Automating your trading removes the hesitation of entering orders by hand, but it does not change your strategy or a prop firm's rules. By mastering these error codes, you ensure your infrastructure is as reliable as your strategy.
Take control of your execution: try Core for 7 days for $7 at PineConnector today, with hosted MT5 through Edge included. After the trial, Core is $59/month unless you cancel.
