MT4 error 0: No error returned

What MQL4 says

0 ERR_NO_ERROR

No error returned

From MQL4's table of error codes, read 24 October 2026. An Expert Advisor reads it with GetLastError() after a call fails; the Experts and Journal tabs print what the EA logs.

What causes it

Nothing failed: MQL4 gives 0 to ERR_NO_ERROR. A log that prints error 0 after a failed order read GetLastError() a second time; MQL4's GetLastError page says the last error is reset after each call.

How to fix it

Read GetLastError() once, right after the call that failed, and keep that value. OrderSend() returns -1 and OrderModify() false when they fail; print the stored value, because a second GetLastError() returns 0.

Source: MQL4 Reference: GetLastError. No MQL4 code is shown because none here was compiled; adapt the steps to your EA.

Other MT4 errors

• MT4 error 1: No error returned, but the result is unknown
• MT4 error 2: Common error
• MT4 error 3: Invalid trade parameters
• MT4 error 130: Invalid stops
• MT4 error 131: Invalid trade volume
• MT4 error 132: Market is closed
• MT4 error 133: Trade is disabled
• MT4 error 134: Not enough money
• MT4 error 136: Off quotes
• MT4 error 4051: Invalid function parameter value
• MT4 error 4107: Invalid price
• MT4 error 4111: Shorts are not allowed
• MT4 error 4112: Automated trading by Expert Advisors/Scripts disabled by trade server
• MT4 error 4200: Object already exists
• MT4 error 5004: Cannot open file