diff --git a/.github/workflows/integration.yml b/.github/workflows/integration.yml
index f772704..fcd1583 100644
--- a/.github/workflows/integration.yml
+++ b/.github/workflows/integration.yml
@@ -94,10 +94,17 @@ jobs:
           cd backend/
           go generate
 
-      - name: Build Executable
+      - name: Build QPep
         run: |
           go build -v -o build/qpep
 
+      - name: Build QPep Tray
+        run: |
+          pushd qpep-tray
+          set CGO_ENABLED=0
+          go build -o ../build/qpep-tray
+          popd
+
       - uses: actions/upload-artifact@v4
         with:
           name: qpep_linux_b${{ github.run_id }}
diff --git a/docs/user-manual.md b/docs/user-manual.md
index 00f8f89..f5f29d6 100644
--- a/docs/user-manual.md
+++ b/docs/user-manual.md
@@ -353,8 +353,6 @@ Usage
 
 ### Client
 
-> The following instructions apply to Windows OS installation
-
 After installing successfully, use the desktop icon to launch the QPep tray application.
 
 ![Tray Launch Icon](resources/5.png){ width=100pt }
diff --git a/workers/client/client_proxy_listener_linux.go b/workers/client/client_proxy_listener_linux.go
index b6204e9..3ff15a4 100644
--- a/workers/client/client_proxy_listener_linux.go
+++ b/workers/client/client_proxy_listener_linux.go
@@ -3,7 +3,7 @@
 package client
 
 import (
-	"errors"
+	stderr "errors"
 	"fmt"
 	"github.com/parvit/qpep/shared/errors"
 	"net"
@@ -90,13 +90,13 @@ const (
 
 func getOriginalDst(clientConn *net.TCPConn) (*net.TCPAddr, *net.TCPConn, error) {
 	if clientConn == nil {
-		return nil, nil, errors.New("ERR: clientConn is nil")
+		return nil, nil, stderr.New("ERR: clientConn is nil")
 	}
 
 	// test if the underlying fd is nil
 	remoteAddr := clientConn.RemoteAddr()
 	if remoteAddr == nil {
-		return nil, nil, errors.New("ERR: clientConn.fd is nil")
+		return nil, nil, stderr.New("ERR: clientConn.fd is nil")
 	}
 
 	fmt.Printf(">> %v\n", clientConn.RemoteAddr())
@@ -128,7 +128,7 @@ func getOriginalDst(clientConn *net.TCPConn) (*net.TCPAddr, *net.TCPConn, error)
 		clientConnFile.Close()
 	} else {
 		errmsg := fmt.Sprintf("ERR: newConn is not a *net.TCPConn, instead it is: %T (%v)", newConn, newConn)
-		return nil, nil, errors.New(errmsg)
+		return nil, nil, stderr.New(errmsg)
 	}
 
 	// attention: IPv4 only!!!