What does macOS kernel return 0xE0004056 (kIOUSBConfigNotFound) mean?

 
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kIOUSBPortWasSuspended kIOUSBEndpointNotFound

kIOUSBConfigNotFound

A configuration is not an interface or endpoint

kIOUSBConfigNotFound means that the requested USB configuration could not be found. A configuration is the top-level descriptor-selected arrangement of interfaces and power requirements; it is not interchangeable with an interface number, alternate setting, or endpoint address. Looking up the wrong level of the descriptor tree is a common cause of confusing diagnostics.

The outcome can depend on the descriptors actually returned by this device at the current speed and firmware revision. A valid configuration may also be unavailable because the caller retained stale descriptor information from an earlier enumeration cycle.

Inspect the descriptor tree

  • Capture the complete configuration descriptor set and record each bConfigurationValue, not only its ordinal position.
  • Record the selected configuration, interface, alternate setting, endpoint address, and negotiated bus speed.
  • Check for re-enumeration, reset, or firmware changes that invalidated cached descriptor references.
  • Do not try to repair this with endpoint recovery commands; the configuration must be selected and present before endpoint work can be addressed.

References


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