What does NTSTATUS 0xC00000B2 (STATUS_PIPE_CONNECTED) mean?

STATUS_PIPE_CONNECTED

A connect operation was attempted on an already connected pipe

The instance is already connected when code attempts an operation that assumes an unconnected listener. Track connect and disconnect ownership so the same server instance is not initialized twice.

The pipe instance is past the listening state. Calling a connect path again on that instance is an ordering error in server code or a race with an already-connected client.

What to inspect

• Check whether ConnectNamedPipe returned after a client connected early.
• Use one pipe instance per active client connection.
• Do not recycle an instance without disconnecting it first.

References for STATUS_PIPE_CONNECTED

• Microsoft Open Specifications: NTSTATUS values
• Microsoft: Named Pipes
• Microsoft: Named Pipe Type, Read, and Wait Modes
• Microsoft: Named Pipe Operations