E_FAIL

General Function Failure

Beckhoff · TwinCAT 2 Automation Interface

What does E_FAIL mean?

The operation failed for an unspecified reason, indicating a general failure. This could happen during NewConfiguration() or ActivateConfiguration(), StartRestartTwinCAT() if the TwinCAT system cannot be started, or ConsumeXml() if the provided XML string is not a valid document.

Additional Steps

Steps 1–2 are listed in Priority Fix.

  1. 3

    For ConsumeXml(), validate the input bstrXML string against the TwinCAT XML schema for correct syntax and structure.

  2. 4

    Re-run the automation script with enhanced logging to pinpoint the exact failure point and context.

Source: Beckhoff TwinCAT 2 Automation Interface
Open Manual (Page 31)