XTLS/Xray-core · error

invalid protocol or invalid user

Error message

invalid protocol or invalid user

What it means

Error "invalid protocol or invalid user" thrown in XTLS/Xray-core.

Source

Thrown at proxy/trojan/server.go:206

		user = s.validator.Get(hexString(first.BytesTo(56)))
		if user == nil {
			// invalid user, let's fallback
			err = errors.New("not a valid user")
			log.Record(&log.AccessMessage{
				From:   conn.RemoteAddr(),
				To:     "",
				Status: log.AccessRejected,
				Reason: err,
			})

			shouldFallback = true
		}
	}

	if isfb && shouldFallback {
		return s.fallback(ctx, err, sessionPolicy, conn, iConn, napfb, first, firstLen, bufferedReader)
	} else if shouldFallback {
		return errors.New("invalid protocol or invalid user")
	}

	clientReader := &ConnReader{Reader: bufferedReader}
	if err := clientReader.ParseHeader(); err != nil {
		log.Record(&log.AccessMessage{
			From:   conn.RemoteAddr(),
			To:     "",
			Status: log.AccessRejected,
			Reason: err,
		})
		return errors.New("failed to create request from: ", conn.RemoteAddr()).Base(err)
	}

	destination := clientReader.Target
	if err := conn.SetReadDeadline(time.Time{}); err != nil {
		return errors.New("unable to set read deadline").Base(err).AtWarning()
	}

View on GitHub (pinned to 7d214f8b09)

When it happens

Trigger: Thrown at proxy/trojan/server.go:206 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of XTLS/Xray-core@7d214f8b09 (2026-08-15). Data as JSON: /api/errors/3d85cadfc637a2e2. Report an issue: GitHub.