When .htaccess password protection fails on Apache (Ubuntu 12.04), the first step is to verify all authentication components:

# Check Apache modules are enabled
sudo a2enmod auth_basic authn_file
sudo service apache2 restart

# Verify .htaccess syntax (should return nothing if valid)
apache2ctl -t

The most frequent issue lies in the AllowOverride directive. Your virtual host configuration needs:

<Directory ~ "public_html/.*">
    AllowOverride AuthConfig
    # Instead of just 'All' which may cause conflicts
</Directory>

Apache requires proper access to the .htpasswd file:

# Set correct ownership and permissions
sudo chown www-data:www-data /home/janeb/.htpasswd
sudo chmod 640 /home/janeb/.htpasswd

# Verify file path in .htaccess
AuthUserFile /home/janeb/.htpasswd  # Absolute path required

Enable detailed logging in Apache's configuration:

# In /etc/apache2/apache2.conf
LogLevel debug
ErrorLog ${APACHE_LOG_DIR}/error.log

# Check logs after authentication attempt
tail -f /var/log/apache2/error.log

If basic auth continues failing, consider these alternatives:

# Option 1: Digest authentication
AuthType Digest
AuthDigestProvider file
AuthUserFile /home/janeb/.htdigest

# Option 2: IP-based restriction
Order deny,allow
Deny from all
Allow from 192.168.1.0/24
Require ip 192.168.1

Browser caching often masks authentication issues:

# Test with curl to bypass browser caching
curl -u username:password http://yoursite.com/protected/

• Verify AuthBasicProvider is set to 'file'
• Confirm .htpasswd contains properly hashed entries (use htpasswd tool)
• Check SELinux/apparmor isn't blocking access (Ubuntu 12.04 specific)
• Ensure no conflicting .htaccess rules in parent directories

When your .htaccess password protection fails silently without prompting for credentials, it's often due to misconfigurations in either Apache's core settings or file permissions. Let's examine the complete diagnostic process.

# Verify these essential settings in your Apache config:
<Directory /path/to/protected/area>
    AllowOverride AuthConfig
    Options +Indexes
    Require all granted
</Directory>

The .htpasswd file must be readable by Apache but secured from public access:

chmod 640 /home/janeb/.htpasswd
chown www-data:janeb /home/janeb/.htpasswd

Ensure the auth_basic module is loaded:

a2enmod auth_basic
apache2ctl -M | grep auth_basic

Check Apache's error logs for authentication-related messages:

tail -f /var/log/apache2/error.log

Here's a working template with enhanced security:

AuthType Basic
AuthName "Restricted Area"
AuthBasicProvider file
AuthUserFile /home/janeb/.htpasswd
AuthGroupFile /dev/null
<Limit GET POST>
    Require valid-user
</Limit>

For UserDir setups, add this to your virtual host:

<Directory /home/*/public_html>
    AllowOverride All
    Options +Indexes +FollowSymLinks
    Require all granted
</Directory>

Create credentials properly using htpasswd:

htpasswd -c /home/janeb/.htpasswd inb351

After making changes, verify syntax and restart Apache:

apache2ctl configtest
systemctl restart apache2