Symptoms
The WriteFile() or ReadFile() function call may fail with the error
ERROR_INVALID_PARAMETER
if you are operating on a named pipe and using overlapped I/O.
Cause
A possible cause for the failure is that the Offset and OffsetHigh members of the OVERLAPPED structure are not set to zero.
Resolution
Set the Offset and OffsetHigh members of your OVERLAPPED structure to zero.
Status
This behavior is by design. The online help for both WriteFile() and ReadFile() state that the Offset and OffsetHigh members of the OVERLAPPED structure must be set to zero or the functions will fail.
More Information
In many cases the function calls may succeed if you do not explicitly set OVERLAPPED.Offset and OVERLAPPED.OffsetHigh to zero. However, this is usually either because the OVERLAPPED structure is static or global and therefore is initialized to zero, or the OVERLAPPED structure is automatic (local) and the contents of that location on the stack are already zero. You should explicitly set the OVERLAPPED.Offset and OVERLAPPED.OffsetHigh structure members to zero.
