What does Windows error code 768 (ERROR_CALLBACK_POP_STACK) mean?

ERROR_CALLBACK_POP_STACK

a user-mode callback frame must be removed after an exception during callback processing.

ERROR_CALLBACK_POP_STACK identifies this condition: Windows uses this control status while unwinding a kernel-to-user callback. An exception occurred in the callback, and the special callback frame needs to be popped so the transition can unwind correctly.

Where the result appears

• window-manager or subsystem callbacks.
• kernel-mediated user-mode callbacks.
• exception dispatch during callback return.
• debug traces involving callback stack frames.

What to collect

• exception record and callback identifier.
• user and kernel stack traces.
• thread context at callback entry and failure.
• whether callback return APIs were invoked in the required order.

Handling and recovery

System components should preserve the special unwind semantics rather than converting the status to a generic failure. Application developers should investigate the original callback exception, invalid state, or corrupted stack that triggered the unwind.

Common misinterpretation

This status describes stack-control work after another exception; it is rarely the root cause. Diagnose the earlier exception first.

References

• Microsoft: System error codes 500–999