diff --git a/README.md b/README.md
index 67999018d..3ced9a731 100755
--- a/README.md
+++ b/README.md
@@ -192,7 +192,7 @@ sh <(curl https://raw.githubusercontent.com/usmannasir/cyberpanel/stable/preUpgr
 | 🐳 Docker    | [Command Execution](guides/Docker_Command_Execution_Guide.md) | Execute commands in containers     |
 | 🤖 Security  | [AI Scanner](guides/AIScannerDocs.md)                         | AI-powered security scanning       |
 | 📧 Email     | [Mautic Setup](guides/MAUTIC_INSTALLATION_GUIDE.md)           | Email marketing platform           |
-| 🎨 Design    | [Custom CSS Guide](guides/CUSTOM_CSS_GUIDE.md)                | Create custom themes for 2.5.5-dev |
+| 🎨 Design    | [Custom CSS Guide](guides/CUSTOM_CSS_GUIDE.md)                | Create custom themes |
 | 🔥 Security  | [Firewall Blocking Feature](guides/FIREWALL_BLOCKING_FEATURE.md) | Advanced security features         |
 
 ---
diff --git a/guides/DEBIAN_13_INSTALLATION_GUIDE.md b/guides/DEBIAN_13_INSTALLATION_GUIDE.md
index f714ac6ff..24e87d0dc 100644
--- a/guides/DEBIAN_13_INSTALLATION_GUIDE.md
+++ b/guides/DEBIAN_13_INSTALLATION_GUIDE.md
@@ -284,18 +284,7 @@ free -h
 
 ### Testing Compatibility
 
-Run the compatibility test script:
-
-```bash
-# Download test script
-wget https://raw.githubusercontent.com/cyberpanel/cyberpanel/main/test_debian13_support.sh
-
-# Make executable
-chmod +x test_debian13_support.sh
-
-# Run test
-sudo ./test_debian13_support.sh
-```
+For comprehensive compatibility testing, refer to the diagnostic commands in the troubleshooting section below.
 
 ## ✅ Verification Checklist
 
diff --git a/test_debian13_support.sh b/test_debian13_support.sh
deleted file mode 100644
index 81650f704..000000000
--- a/test_debian13_support.sh
+++ /dev/null
@@ -1,430 +0,0 @@
-#!/bin/bash
-
-# Debian 13 Support Test Script for CyberPanel
-# This script tests the compatibility of CyberPanel with Debian 13
-
-set -e
-
-# Colors for output
-RED='\033[0;31m'
-GREEN='\033[0;32m'
-YELLOW='\033[1;33m'
-BLUE='\033[0;34m'
-NC='\033[0m' # No Color
-
-# Test results
-TESTS_PASSED=0
-TESTS_FAILED=0
-TESTS_TOTAL=0
-
-# Function to print colored output
-print_status() {
-    echo -e "${BLUE}[INFO]${NC} $1"
-}
-
-print_success() {
-    echo -e "${GREEN}[SUCCESS]${NC} $1"
-    ((TESTS_PASSED++))
-}
-
-print_warning() {
-    echo -e "${YELLOW}[WARNING]${NC} $1"
-}
-
-print_error() {
-    echo -e "${RED}[ERROR]${NC} $1"
-    ((TESTS_FAILED++))
-}
-
-print_test_header() {
-    echo -e "\n${BLUE}=== $1 ===${NC}"
-    ((TESTS_TOTAL++))
-}
-
-# Function to run a test
-run_test() {
-    local test_name="$1"
-    local test_command="$2"
-    local expected_result="$3"
-    
-    print_test_header "$test_name"
-    
-    if eval "$test_command" >/dev/null 2>&1; then
-        if [[ "$expected_result" == "success" ]]; then
-            print_success "$test_name passed"
-            return 0
-        else
-            print_error "$test_name failed (unexpected success)"
-            return 1
-        fi
-    else
-        if [[ "$expected_result" == "failure" ]]; then
-            print_success "$test_name passed (expected failure)"
-            return 0
-        else
-            print_error "$test_name failed"
-            return 1
-        fi
-    fi
-}
-
-# Function to check OS detection
-test_os_detection() {
-    print_test_header "OS Detection Test"
-    
-    # Check if we're on Debian 13
-    if [[ -f /etc/os-release ]]; then
-        source /etc/os-release
-        if [[ "$ID" == "debian" && "$VERSION_ID" == "13" ]]; then
-            print_success "Debian 13 detected correctly"
-        else
-            print_warning "Not running on Debian 13 (Current: $ID $VERSION_ID)"
-            print_status "This test is designed for Debian 13, but will continue with current OS"
-        fi
-    else
-        print_error "Cannot detect OS - /etc/os-release not found"
-        return 1
-    fi
-}
-
-# Function to test CyberPanel OS detection logic
-test_cyberpanel_os_detection() {
-    print_test_header "CyberPanel OS Detection Logic Test"
-    
-    # Test the OS detection logic from cyberpanel.sh
-    if grep -q -E "Debian GNU/Linux 11|Debian GNU/Linux 12|Debian GNU/Linux 13" /etc/os-release; then
-        print_success "CyberPanel OS detection logic recognizes Debian 11/12/13"
-    else
-        print_error "CyberPanel OS detection logic does not recognize current Debian version"
-        return 1
-    fi
-}
-
-# Function to test package manager compatibility
-test_package_manager() {
-    print_test_header "Package Manager Compatibility Test"
-    
-    # Test apt-get availability
-    if command -v apt-get >/dev/null 2>&1; then
-        print_success "apt-get package manager is available"
-    else
-        print_error "apt-get package manager not found"
-        return 1
-    fi
-    
-    # Test apt-get update (dry run)
-    if apt-get update --dry-run >/dev/null 2>&1; then
-        print_success "apt-get update works correctly"
-    else
-        print_warning "apt-get update failed (may be network related)"
-    fi
-}
-
-# Function to test systemd compatibility
-test_systemd_compatibility() {
-    print_test_header "Systemd Compatibility Test"
-    
-    # Test systemctl availability
-    if command -v systemctl >/dev/null 2>&1; then
-        print_success "systemctl is available"
-    else
-        print_error "systemctl not found"
-        return 1
-    fi
-    
-    # Test systemd status
-    if systemctl is-system-running >/dev/null 2>&1; then
-        print_success "systemd is running"
-    else
-        print_warning "systemd status unclear"
-    fi
-}
-
-# Function to test Python compatibility
-test_python_compatibility() {
-    print_test_header "Python Compatibility Test"
-    
-    # Test Python 3 availability
-    if command -v python3 >/dev/null 2>&1; then
-        local python_version=$(python3 --version 2>&1 | cut -d' ' -f2)
-        print_success "Python 3 is available: $python_version"
-        
-        # Check if Python version is compatible (3.6+)
-        local major_version=$(echo "$python_version" | cut -d'.' -f1)
-        local minor_version=$(echo "$python_version" | cut -d'.' -f2)
-        
-        if [[ $major_version -ge 3 && $minor_version -ge 6 ]]; then
-            print_success "Python version is compatible (3.6+)"
-        else
-            print_warning "Python version may not be fully compatible (requires 3.6+)"
-        fi
-    else
-        print_error "Python 3 not found"
-        return 1
-    fi
-    
-    # Test pip3 availability
-    if command -v pip3 >/dev/null 2>&1; then
-        print_success "pip3 is available"
-    else
-        print_warning "pip3 not found (may need to be installed)"
-    fi
-}
-
-# Function to test web server compatibility
-test_web_server_compatibility() {
-    print_test_header "Web Server Compatibility Test"
-    
-    # Test Apache2 availability
-    if command -v apache2 >/dev/null 2>&1; then
-        print_success "Apache2 is available"
-    else
-        print_warning "Apache2 not found (will be installed by CyberPanel)"
-    fi
-    
-    # Test if Apache2 can be installed
-    if apt-cache show apache2 >/dev/null 2>&1; then
-        print_success "Apache2 package is available in repositories"
-    else
-        print_error "Apache2 package not found in repositories"
-        return 1
-    fi
-}
-
-# Function to test required packages availability
-test_required_packages() {
-    print_test_header "Required Packages Availability Test"
-    
-    local required_packages=(
-        "curl"
-        "wget"
-        "git"
-        "build-essential"
-        "python3-dev"
-        "python3-pip"
-        "python3-venv"
-        "software-properties-common"
-        "apt-transport-https"
-        "ca-certificates"
-        "gnupg"
-    )
-    
-    local available_count=0
-    local total_count=${#required_packages[@]}
-    
-    for package in "${required_packages[@]}"; do
-        if apt-cache show "$package" >/dev/null 2>&1; then
-            print_success "$package is available"
-            ((available_count++))
-        else
-            print_warning "$package not found in repositories"
-        fi
-    done
-    
-    print_status "Available packages: $available_count/$total_count"
-    
-    if [[ $available_count -ge $((total_count * 8 / 10)) ]]; then
-        print_success "Most required packages are available"
-    else
-        print_warning "Many required packages are missing"
-    fi
-}
-
-# Function to test LiteSpeed repository compatibility
-test_litespeed_repo_compatibility() {
-    print_test_header "LiteSpeed Repository Compatibility Test"
-    
-    # Test if we can access LiteSpeed Debian repository
-    if curl -s --head "http://rpms.litespeedtech.com/debian/" | head -n 1 | grep -q "200 OK"; then
-        print_success "LiteSpeed Debian repository is accessible"
-    else
-        print_warning "LiteSpeed Debian repository may not be accessible"
-    fi
-    
-    # Test if we can download the repository setup script
-    if wget --spider "http://rpms.litespeedtech.com/debian/enable_lst_debian_repo.sh" 2>/dev/null; then
-        print_success "LiteSpeed repository setup script is available"
-    else
-        print_warning "LiteSpeed repository setup script may not be available"
-    fi
-}
-
-# Function to test MariaDB compatibility
-test_mariadb_compatibility() {
-    print_test_header "MariaDB Compatibility Test"
-    
-    # Test MariaDB repository accessibility
-    if curl -s --head "https://mariadb.org/mariadb_release_signing_key.pgp" | head -n 1 | grep -q "200 OK"; then
-        print_success "MariaDB signing key is accessible"
-    else
-        print_warning "MariaDB signing key may not be accessible"
-    fi
-    
-    # Test if MariaDB packages are available
-    if apt-cache show mariadb-server >/dev/null 2>&1; then
-        print_success "MariaDB packages are available in repositories"
-    else
-        print_warning "MariaDB packages not found in default repositories"
-    fi
-}
-
-# Function to test network connectivity
-test_network_connectivity() {
-    print_test_header "Network Connectivity Test"
-    
-    local test_urls=(
-        "https://github.com"
-        "https://pypi.org"
-        "http://rpms.litespeedtech.com"
-        "https://mariadb.org"
-    )
-    
-    local accessible_count=0
-    local total_count=${#test_urls[@]}
-    
-    for url in "${test_urls[@]}"; do
-        if curl -s --head "$url" >/dev/null 2>&1; then
-            print_success "$url is accessible"
-            ((accessible_count++))
-        else
-            print_warning "$url is not accessible"
-        fi
-    done
-    
-    print_status "Accessible URLs: $accessible_count/$total_count"
-    
-    if [[ $accessible_count -ge $((total_count * 3 / 4)) ]]; then
-        print_success "Network connectivity is good"
-    else
-        print_warning "Network connectivity may be limited"
-    fi
-}
-
-# Function to test system resources
-test_system_resources() {
-    print_test_header "System Resources Test"
-    
-    # Test available memory
-    local total_memory=$(free -m | awk 'NR==2{print $2}')
-    if [[ $total_memory -ge 1024 ]]; then
-        print_success "Sufficient memory available: ${total_memory}MB"
-    else
-        print_warning "Low memory: ${total_memory}MB (recommended: 1GB+)"
-    fi
-    
-    # Test available disk space
-    local available_space=$(df / | awk 'NR==2{print $4}')
-    local available_gb=$((available_space / 1024 / 1024))
-    if [[ $available_gb -ge 10 ]]; then
-        print_success "Sufficient disk space: ${available_gb}GB"
-    else
-        print_warning "Low disk space: ${available_gb}GB (recommended: 10GB+)"
-    fi
-    
-    # Test CPU cores
-    local cpu_cores=$(nproc)
-    if [[ $cpu_cores -ge 2 ]]; then
-        print_success "Sufficient CPU cores: $cpu_cores"
-    else
-        print_warning "Limited CPU cores: $cpu_cores (recommended: 2+)"
-    fi
-}
-
-# Function to run all tests
-run_all_tests() {
-    echo -e "${BLUE}========================================${NC}"
-    echo -e "${BLUE}  CyberPanel Debian 13 Compatibility Test${NC}"
-    echo -e "${BLUE}========================================${NC}\n"
-    
-    test_os_detection
-    test_cyberpanel_os_detection
-    test_package_manager
-    test_systemd_compatibility
-    test_python_compatibility
-    test_web_server_compatibility
-    test_required_packages
-    test_litespeed_repo_compatibility
-    test_mariadb_compatibility
-    test_network_connectivity
-    test_system_resources
-    
-    echo -e "\n${BLUE}========================================${NC}"
-    echo -e "${BLUE}  Test Results Summary${NC}"
-    echo -e "${BLUE}========================================${NC}"
-    echo -e "Total Tests: $TESTS_TOTAL"
-    echo -e "Passed: ${GREEN}$TESTS_PASSED${NC}"
-    echo -e "Failed: ${RED}$TESTS_FAILED${NC}"
-    
-    if [[ $TESTS_FAILED -eq 0 ]]; then
-        echo -e "\n${GREEN}✅ All tests passed! Debian 13 appears to be compatible with CyberPanel.${NC}"
-        return 0
-    elif [[ $TESTS_FAILED -le 2 ]]; then
-        echo -e "\n${YELLOW}⚠️  Most tests passed. Debian 13 should be compatible with minor issues.${NC}"
-        return 0
-    else
-        echo -e "\n${RED}❌ Multiple tests failed. Debian 13 may have compatibility issues.${NC}"
-        return 1
-    fi
-}
-
-# Function to show usage
-show_usage() {
-    echo "Usage: $0 [OPTIONS]"
-    echo ""
-    echo "Options:"
-    echo "  -h, --help     Show this help message"
-    echo "  -v, --verbose  Enable verbose output"
-    echo "  --quick        Run only essential tests"
-    echo ""
-    echo "This script tests CyberPanel compatibility with Debian 13."
-    echo "Run as root for best results."
-}
-
-# Main execution
-main() {
-    local verbose=false
-    local quick=false
-    
-    # Parse command line arguments
-    while [[ $# -gt 0 ]]; do
-        case $1 in
-            -h|--help)
-                show_usage
-                exit 0
-                ;;
-            -v|--verbose)
-                verbose=true
-                shift
-                ;;
-            --quick)
-                quick=true
-                shift
-                ;;
-            *)
-                echo "Unknown option: $1"
-                show_usage
-                exit 1
-                ;;
-        esac
-    done
-    
-    # Check if running as root
-    if [[ $EUID -ne 0 ]]; then
-        print_warning "Not running as root. Some tests may fail."
-        print_status "Consider running: sudo $0"
-    fi
-    
-    # Run tests
-    if [[ "$quick" == "true" ]]; then
-        print_status "Running quick compatibility test..."
-        test_os_detection
-        test_cyberpanel_os_detection
-        test_package_manager
-        test_systemd_compatibility
-    else
-        run_all_tests
-    fi
-}
-
-# Run main function
-main "$@"