MT4 Error Handler

string returnError(int errorCode) { //1
//Translates and returns an Error Code
//Source for translations: http://www.iexpertadvisor.com/metaTrader4errors.asp

switch(errorCode) { //2
case 0: return("No error returned.");
case 1: return("No error returned, but the result is unknown.");
case 2: return("Common error.");
case 3: return("Invalid trade parameters.");
case 4: return("Trade server is busy.");
case 5: return("Old version of the client terminal.");
case 6: return("No connection with trade server.");
case 7: return("Not enough rights.");
case 8: return("Too frequent requests.");
case 9: return("Malfunction trade operation.");
case 64: return("Account disabled.");
case 65: return("Invalid account.");
case 128: return("Trade timeout.");
case 129: return("Invalide price.");
case 130: return("Invalid stops.");
case 131: return("Invalid trade volume.");
case 132: return("Market is closed.");
case 133: return("Trade is disabled.");
case 134: return("Not enough money.");
case 135: return("Price changed.");
case 136: return("Off quotes.");
case 137: return("Broker is busy.");
case 138: return("Requote.");
case 139: return("Order is locked.");
case 140: return("Long positions only allowed");
case 141: return("Too many requests");
case 145: return("Modification denied because order too close to market.");
case 146: return("Trade context is busy.");
} //2
return("Unknown Error Code.");
} //1

//Translates and returns an MT 4 error code
//Source for translations: http://www.iexpertadvisor.com/metaTrader4errors.asp
//and http://docs.mql4.com/runtime/errors

string returnError(int errorCode)

{ //1

switch(errorCode)

{ //2

case 0: return("No error returned.");
case 1: return("No error returned, but the result is unknown.");
case 2: return("Common error.");
case 3: return("Invalid trade parameters.");
case 4: return("Trade server is busy.");
case 5: return("Old version of the client terminal.");
case 6: return("No connection with trade server.");
case 7: return("Not enough rights.");
case 8: return("Too frequent requests.");
case 9: return("Malfunction trade operation.");
case 64: return("Account disabled.");
case 65: return("Invalid account.");
case 128: return("Trade timeout.");
case 129: return("Invalide price.");
case 130: return("Invalid stops.");
case 131: return("Invalid trade volume.");
case 132: return("Market is closed.");
case 133: return("Trade is disabled.");
case 134: return("Not enough money.");
case 135: return("Price changed.");
case 136: return("Off quotes.");
case 137: return("Broker is busy.");
case 138: return("Requote.");
case 139: return("Order is locked.");
case 140: return("Long positions only allowed");
case 141: return("Too many requests");
case 145: return("Modification denied because order too close to market.");
case 146: return("Trade context is busy.");
case 4001: return("Execution halted: Wrong function pointer.");
case 4003: return("Execution halted: No memory for call stack.");
case 4004: return("Execution halted: Recursive stack overflow.");
case 4006: return("Execution halted: No memory for param string.");
case 4007: return("Execution halted: No memory for temp string.");
case 4010: return("Execution halted: No memory for array string.");
case 4011: return("Execution halted: Too long string.");
case 4012: return("Execution halted: Remainder from zero divide.");
case 4013: return("Execution halted: Zero divide.");
case 4014: return("Execution halted: Unknown command.");
case 4018: return("Execution halted: Cannot load library.");
case 4019: return("Execution halted: Cannot call function.");
case 4017: return("Execution halted: DLL calls not allowed.");
case 4020: return("Execution halted: External calls not allowed.");
case 4002: return("Execution continues: Array index out of range.");
case 4008: return("Execution continues: Not initialized string.");
case 4009: return("Execution continues: Not initialized arraystring.");
case 4021: return("Execution continues: No memory for returned string.");
case 4000: return("Execution continues: No MQL.");
case 4014: return("Hardware/software failure: Unknown command.");
case 4016: return("Hardware/software failure: Not initialized array.");
case 4050: return("Hardware/software failure: Invalid function parameters count.");
case 4052: return("Hardware/software failure: String function internal.");
case 4067: return("Hardware/software failure: Trade Error.");
case 4207: return("Hardware/software failure: Some object error.");
} //2

return("Unknown Error Code.");

} //1

Okay, this time I am including a hell of a lot of the esoteric errors that can happen during runtime. Although you won't be able to trace the error to the line number in your code, you can at least see the method that is causing it. Anyone who finds more can add to this list. Note that some error codes can be caused by several different methods, so I have included all possibilities in each return:

//Translates and returns an MT 4 error code
//Source for translations: http://www.iexpertadvisor.com/metaTrader4errors.asp
//and http://docs.mql4.com/runtime/errors

string returnError(int errorCode)

{ //1

switch(errorCode)

{ //2

case 0: return("OrderModify: No error.");
case 1: return("No error returned, but the result is unknown.");
case 2: return("Common error.");
case 3: return("Invalid trade parameters.");
case 4: return("Trade server is busy.");
case 5: return("Old version of the client terminal.");
case 6: return("No connection with trade server.");
case 7: return("Not enough rights.");
case 8: return("Too frequent requests.");
case 9: return("Malfunction trade operation.");
case 64: return("Account disabled.");
case 65: return("Invalid account.");
case 128: return("Trade timeout.");
case 129: return("Invalide price.");
case 130: return("Invalid stops.");
case 131: return("Invalid trade volume.");
case 132: return("Market is closed.");
case 133: return("Trade is disabled.");
case 134: return("AccountFreeMarginCheck: Not enough money.");
case 135: return("Price changed.");
case 136: return("Off quotes.");
case 137: return("Broker is busy.");
case 138: return("Requote.");
case 139: return("Order is locked.");
case 140: return("Long positions only allowed");
case 141: return("Too many requests");
case 145: return("Modification denied because order too close to market.");
case 146: return("Trade context is busy.");
case 4000: return("(Execution continues) No MQL.");
case 4001: return("(Execution halted) Wrong function pointer.");
case 4002: return("ObjectName/StringGetChar/StringSetChar: (Execution continues) Array index out of range.");
case 4003: return("(Execution halted) No memory for call stack.");
case 4004: return("(Execution halted) Recursive stack overflow.");
case 4006: return("(Execution halted) No memory for param string.");
case 4007: return("(Execution halted) No memory for temp string.");
case 4008: return("StringGetChar/StringSetChar/WindowFind/WindowHandle: (Execution continues) Not initialized string.");
case 4009: return("(Execution continues) Not initialized arraystring.");
case 4010: return("(Execution halted) No memory for array string.");
case 4011: return("FileReadString/StringSetChar/StringSubstr: (Execution halted) Too long string.");
case 4012: return("(Execution halted) Remainder from zero divide.");
case 4013: return("MathMod: (Execution halted) Zero divide.");
case 4014: return("Hardware/software failure: (Execution halted) Uknown command.");
case 4016: return("Hardware/software failure: Not initialized array.");
case 4017: return("(Execution halted) DLL calls not allowed.");
case 4018: return("(Execution halted) Cannot load library.");
case 4019: return("(Execution halted) Cannot call function.");
case 4020: return("(Execution halted) External calls not allowed.");
case 4021: return("(Execution continues) No memory for returned string.");
case 4050: return("Hardware/software failure: Invalid function parameters count.");
case 4051: return("AccountFreeMarginCheck/OrderSend/OrderClose/OrderCloseBy/OrderDelete/OrderModify/ArrayBsearch/ArrayCopy/ArrayCopySeries/ArrayInitialize/ArrayMaximum/ArrayMinimum/ArrayRange/ArrayResize/ArraySort/FileClose/FileFlush/FileIsEnding/FileIsLineEnding/FileOpen/FileOpenHistory/FileReadArray/FileReadDouble/FileReadInteger/FileReadNumber/FileReadString/FileSeek/FileSize/FileTell/FileWrite/FileWriteDouble/FileWriteInteger/FileWriteString/FileWriteArray/iCustom/IndicatorBuffers/IndicatorDigits/IndicatorShortName/MarketInfo/MathArccos/MathArcsin/MathSqrt/ObjectCreate/ObjectGetFiboDescription/ObjectMove/ObjectName/ObjectSetFiboDescription/SetIndexArrow/SetIndexBuffer/SetIndexDrawBegin/SetIndexEmptyValue/SetIndexLabel/SetIndexShift/SetIndexStyle/SetLevelValue/StringSetChar/WindowScreenShot: Invalid function parameter value.");
case 4052: return("Hardware/software failure: String function internal.");
case 4053: return("ArrayBsearch/ArrayCopy/ArrayCopyRates/ArrayCopySeries/ArrayDimension/ArrayGetAsSeries/ArrayInitialize/ArrayIsSeries/ArrayMaximum/ArrayMinimum/ArrayRange/ArrayResize/ArraySetAsSeries/ArraySize/ArraySort/FileReadArray/OnArray: Some array error.");
case 4054: return("ArrayCopySeries/ArraySort/SetIndexBuffer: Incorrect series array using.");
case 4055: return("OrderSend/OrderClose/OrderCloseBy/OrderDelete/OrderModify/MessageBox/SendFTP/Sleep: Custom indicator error.");
case 4056: return("ArrayCopy/ArrayCopyRates/ArrayCopySeries/SetIndexBuffer: Incompatible Arrays");
case 4057: return("GlobalVariableDel/GlobalVariablesDeleteAll/GlobalVariableSet: Global variable processing.");
case 4058: return("GlobalVariableGet/GlobalVariableSet/GlobalVariableSetOnCondition: Global variable not found.");
case 4059: return("MarketInfo/MessageBox/SendFTP/SendMail/WindowIsVisible/WindowFind/WindowHandle: Function not allowed in testing.");
case 4060: return("SendMail: Function not confirmed.");
case 4061: return("SendMail: Send mail error.");
case 4062: return("AccountFreeMarginCheck/ArrayCopySeries/IndicatorShortName/MarketInfo/MessageBox/ObjectDelete/OrderSend/ArrayCopyRates/FileWriteString/GlobalVariableCheck/GlobalVariableDel/GlobalVariableGet/GlobalVariablesDeleteAll/GlobalVariableSet/GlobalVariableSetOnCondition/iCustom/ObjectCreate/ObjectDescription/ObjectFind/ObjectGet/ObjectGetFiboDescription/ObjectGetShiftByValue/ObjectGetValueByShift/ObjectMove/ObjectSet/ObjectSetText/ObjectSetFiboDescription/ObjectType/SendFTP/SendMail/SetIndexLabel/StringFind/StringGetChar/StringLen/StringSetChar/StringSubstr/StringTrimLeft/StringTrimRight/WindowFind/WindowHandle: String parameter expected.");
case 4063: return("AccountFreeMarginCheck/OrderSend/OrderClose/OrderCloseBy/OrderModify/ArrayRange: Integer parameter expected.");
case 4065: return("ArrayBsearch/ArrayCopy/ArrayCopyRates/ArrayCopySeries/ArrayDimension/ArrayGetAsSeries/ArrayInitialize/ArrayIsSeries/ArrayMaximum/ArrayMinimum/ArrayRange/ArrayResize/ArraySetAsSeries/ArraySize/ArraySort/OnArray: Array as parameter expected.");
case 4066: return("ArrayCopySeries/technical indicators/series access: History will updated.");
case 4067: return("Hardware/software failure: Trade Error.");
case 4099: return("FileReadArray/FileReadDouble/FileReadInteger/FileReadNumber/FileReadString: End of file.");
case 4100: return("FileDelete/FileOpen/FileOpenHistory/FileReadArray/FileReadNumber/FileReadString/FileWrite/FileWriteDouble/FileWriteInteger/FileWriteString/FileWriteArray: Some file error.");
case 4101: return("FileDelete/FileOpen/FileOpenHistory/PlaySound/WindowScreenShot: Wrong file name.");
case 4102: return("FileOpen/FileOpenHistory: Too may files open.");
case 4103: return("FileOpen/FileOpenHistory: Cannot open file.");
case 4104: return("FileReadArray/FileReadDouble/FileReadInteger/FileReadNumber/FileReadString/FileWriteDouble/FileWriteInteger/FileWriteString/FileWriteArray: Incompatible file access.");
case 4105: return("OrderClosePrice/OrderCloseTime/OrderComment/OrderCommission/OrderExpiration/OrderLots/OrderMagicNumber/OrderOpenPrice/OrderOpenTime/OrderPrint/OrderProfit/OrderStopLoss/OrderSwap/OrderSymbol/OrderTakeProfit/OrderTicket/OrderType: No order selected.");
case 4106: return("AccountFreeMarginCheck/OrderDelete: Unknown symbol.");
case 4107: return("OrderSend/OrderClose/OrderModify: Invalid price parameter.");
case 4106: return("OrderSend/OrderClose/OrderCloseBy/OrderDelete/OrderModify/MarketInfo: Unknown symbol.");
case 4108: return("OrderClose/OrderCloseBy/OrderDelete/OrderModify: Invalid ticket.");
case 4109: return("OrderSend/OrderClose/OrderCloseBy/OrderDelete/OrderModify: Trade not allowed.");
case 4110: return("OrderSend: Longs not allowed.");
case 4111: return("OrderSend: Shorts not allowed.");
case 4200: return("ObjectCreate: Object already exists.");
case 4201: return("ObjectGet/ObjectGetFiboDescription/ObjectSet/ObjectSetFiboDescription: Unknown object property.");
case 4202: return("ObjectDelete/ObjectDescription/ObjectGet/ObjectGetFiboDescription/ObjectGetShiftByValue/ObjectGetValueByShift/ObjectMove/ObjectSet/ObjectSetText/ObjectSetFiboDescription/ObjectType: Object does not exist.");
case 4203: return("ObjectCreate/ObjectGetFiboDescription/ObjectSetFiboDescription: Unknown object type.");
case 4204: return("ObjectCreate/ObjectDelete/ObjectDescription/ObjectFind/ObjectGet/ObjectGetFibDescription/ObjectGetShiftByValue/ObjectGetValueByShift/ObjectMove/ObjectSet/ObjectSetText/ObjectSetFiboDescription/ObjectType: No object name.");
case 4205: return("ObjectGetShiftByValue/ObjectGetValueByShift: Object coordinates error.");
case 4206: return("ObjectCreate: No specified sub window.");
case 4207: return("Hardware/software failure: Some object error.");
} //2

return("Unknown Error Code.");

} //1

There is a problem with the code I posted previously. A string has a character limit of about 350. This code accounts for that (I had to truncate some of the possible methods that threw the error, and group them into broader catagories). The purpose of the error handler is to return something sensible back to your phone via SMS or email...

Also, I formatted the code to make it not word wrap... should print out on one page easily within your code.

Best,
Tom

// ###################################################################################

//Translates and returns an MT 4 error code
//Source for translations: http://www.iexpertadvisor.com/metaTrader4errors.asp
//and http://docs.mql4.com/runtime/errors

string returnError(int errorCode)

{ //1

switch(errorCode)

{ //2

case 0: return("No error.");
case 1: return("No error returned, but the result is unknown.");
case 2: return("Common error.");
case 3: return("Invalid trade parameters.");
case 4: return("Trade server is busy.");
case 5: return("Old version of the client terminal.");
case 6: return("No connection with trade server.");
case 7: return("Not enough rights.");
case 8: return("Too frequent requests.");
case 9: return("Malfunction trade operation.");
case 64: return("Account disabled.");
case 65: return("Invalid account.");
case 128: return("Trade timeout.");
case 129: return("Invalid price.");
case 130: return("Invalid stops.");
case 131: return("Invalid trade volume.");
case 132: return("Market is closed.");
case 133: return("Trade is disabled.");
case 134: return("AccountFreeMarginCheck: Not enough money.");
case 135: return("Price changed.");
case 136: return("Off quotes.");
case 137: return("Broker is busy.");
case 138: return("Requote.");
case 139: return("Order is locked.");
case 140: return("Long positions only allowed");
case 141: return("Too many requests");
case 145: return("Modification denied because order too close to market.");
case 146: return("Trade context is busy.");
case 4000: return("(Execution continues) No MQL.");
case 4001: return("(Execution halted) Wrong function pointer.");
case 4002: return("ObjectName/StringGetChar/StringSetChar: (Execution continues) A" +
"rray index out of range.");
case 4003: return("(Execution halted) No memory for call stack.");
case 4004: return("(Execution halted) Recursive stack overflow.");
case 4006: return("(Execution halted) No memory for param string.");
case 4007: return("(Execution halted) No memory for temp string.");
case 4008: return("StringGetChar/StringSetChar/WindowFind/WindowHandle: (Execution " +
"continues) Not initialized string.");
case 4009: return("(Execution continues) Not initialized arraystring.");
case 4010: return("(Execution halted) No memory for array string.");
case 4011: return("FileReadString/StringSetChar/StringSubstr: (Execution halted) To" +
"o long string.");
case 4012: return("(Execution halted) Remainder from zero divide.");
case 4013: return("MathMod: (Execution halted) Zero divide.");
case 4014: return("Hardware/software failure: (Execution halted) Unknown command.");
case 4016: return("Hardware/software failure: Not initialized array.");
case 4017: return("(Execution halted) DLL calls not allowed.");
case 4018: return("(Execution halted) Cannot load library.");
case 4019: return("(Execution halted) Cannot call function.");
case 4020: return("(Execution halted) External calls not allowed.");
case 4021: return("(Execution continues) No memory for returned string.");
case 4050: return("Hardware/software failure: Invalid function parameters count.");
case 4051: return("AccountFreeMarginCheck/iCustom/IndicatorBuffers/IndicatorDigits" +
"/IndicatorShortName/MarketInfo/MathArccos/MathArcsin/MathSqrt/S" +
"etLevelValue/StringSetChar/WindowScreenShot/*ORDER/ARRAY/FILE/O" +
"BJECT/INDEX FUNCTIONS: Invalid function parameter value");
case 4052: return("Hardware/software failure: String function internal.");
case 4053: return("ArrayBsearch/ArrayCopy/ArrayCopyRates/ArrayCopySeries/ArrayDime" +
"nsion/ArrayGetAsSeries/ArrayInitialize/ArrayIsSeries/ArrayMaxim" +
"um/ArrayMinimum/ArrayRange/ArrayResize/ArraySetAsSeries/ArraySi" +
"ze/ArraySort/FileReadArray/OnArray: Some array error.");
case 4054: return("ArrayCopySeries/ArraySort/SetIndexBuffer: Incorrect series arra" +
"y using.");
case 4055: return("OrderSend/OrderClose/OrderCloseBy/OrderDelete/OrderModify/Messa" +
"geBox/SendFTP/Sleep: Custom indicator error.");
case 4056: return("ArrayCopy/ArrayCopyRates/ArrayCopySeries/SetIndexBuffer: Incomp" +
"atible Arrays");
case 4057: return("GlobalVariableDel/GlobalVariablesDeleteAll/GlobalVariableSet: G" +
"lobal variable processing.");
case 4058: return("GlobalVariableGet/GlobalVariableSet/GlobalVariableSetOnConditio" +
"n: Global variable not found.");
case 4059: return("MarketInfo/MessageBox/SendFTP/SendMail/WindowIsVisible/WindowFi" +
"nd/WindowHandle: Function not allowed in testing.");
case 4060: return("SendMail: Function not confirmed.");
case 4061: return("SendMail: Send mail error.");
case 4062: return("AccountFreeMarginCheck/ArrayCopySeries/IndicatorShortName/Marke" +
"tInfo/MessageBox/OrderSend/ArrayCopyRates/FileWriteString/iCust" +
"om/SendFTP/SendMail/SetIndexLabel/WindowFind/WindowHandle/*GLOB" +
"AL VARIABLE/STRING/OBJECT functions: String parameter expected.");
case 4063: return("AccountFreeMarginCheck/OrderSend/OrderClose/OrderCloseBy/OrderM" +
"odify/ArrayRange: Integer parameter expected.");
case 4065: return("ArrayBsearch/ArrayCopy/ArrayCopyRates/ArrayCopySeries/ArrayDime" +
"nsion/ArrayGetAsSeries/ArrayInitialize/ArrayIsSeries/ArrayMaxim" +
"um/ArrayMinimum/ArrayRange/ArrayResize/ArraySetAsSeries/ArraySi" +
"ze/ArraySort/OnArray: Array as parameter expected.");
case 4066: return("ArrayCopySeries/technical indicators/series access: History wil" +
"l updated.");
case 4067: return("Hardware/software failure: Trade Error.");
case 4099: return("FileReadArray/FileReadDouble/FileReadInteger/FileReadNumber/Fil" +
"eReadString: End of file.");
case 4100: return("FileDelete/FileOpen/FileOpenHistory/FileReadArray/FileReadNumbe" +
"r/FileReadString/FileWrite/FileWriteDouble/FileWriteInteger/Fil" +
"eWriteString/FileWriteArray: Some file error.");
case 4101: return("FileDelete/FileOpen/FileOpenHistory/PlaySound/WindowScreenShot:" +
" Wrong file name.");
case 4102: return("FileOpen/FileOpenHistory: Too may files open.");
case 4103: return("FileOpen/FileOpenHistory: Cannot open file.");
case 4104: return("FileReadArray/FileReadDouble/FileReadInteger/FileReadNumber/Fil" +
"eReadString/FileWriteDouble/FileWriteInteger/FileWriteString/Fi" +
"leWriteArray: Incompatible file access.");
case 4105: return("OrderClosePrice/OrderCloseTime/OrderComment/OrderCommission/Ord" +
"erExpiration/OrderLots/OrderMagicNumber/OrderOpenPrice/OrderOpe" +
"nTime/OrderPrint/OrderProfit/OrderStopLoss/OrderSwap/OrderSymbo" +
"l/OrderTakeProfit/OrderTicket/OrderType: No order selected.");
case 4106: return("AccountFreeMarginCheck/OrderDelete: Unknown symbol.");
case 4107: return("OrderSend/OrderClose/OrderModify: Invalid price parameter.");
case 4106: return("OrderSend/OrderClose/OrderCloseBy/OrderDelete/OrderModify/Marke" +
"tInfo: Unknown symbol.");
case 4108: return("OrderClose/OrderCloseBy/OrderDelete/OrderModify: Invalid ticket");
case 4109: return("OrderSend/OrderClose/OrderCloseBy/OrderDelete/OrderModify: Trad" +
"e not allowed.");
case 4110: return("OrderSend: Longs not allowed.");
case 4111: return("OrderSend: Shorts not allowed.");
case 4200: return("ObjectCreate: Object already exists.");
case 4201: return("ObjectGet/ObjectGetFiboDescription/ObjectSet/ObjectSetFiboDescr" +
"iption: Unknown object property.");
case 4202: return("ObjectDelete/ObjectDescription/ObjectGet/ObjectGetFiboDescripti" +
"on/ObjectGetShiftByValue/ObjectGetValueByShift/ObjectMove/Objec" +
"tSet/ObjectSetText/ObjectSetFiboDescription/ObjectType: Object " +
"does not exist.");
case 4203: return("ObjectCreate/ObjectGetFiboDescription/ObjectSetFiboDescription:" +
" Unknown object type.");
case 4204: return("ObjectCreate/ObjectDelete/ObjectDescription/ObjectFind/ObjectGe" +
"t/ObjectGetFibDescription/ObjectGetShiftByValue/ObjectGetValueB" +
"yShift/ObjectMove/ObjectSet/ObjectSetText/ObjectSetFiboDescript" +
"ion/ObjectType: No object name.");
case 4205: return("ObjectGetShiftByValue/ObjectGetValueByShift: Object coordinates" +
" error.");
case 4206: return("ObjectCreate: No specified sub window.");
case 4207: return("Hardware/software failure: Some object error.");
} //2

return("Unknown Error Code.");

} //1