I think, I fixed it.

navbar.php

@@ -1 +1 @@
-<?php 
if (isset($_SESSION['user_id'])){ 
	$login = true;
} else { 
	$login = false;
}
?>

<ul class="topnav">
	<li>
		<?php 
 
if (isset($_SESSION['user_id'])){ 
 
	$login = true;
 
} else { 
 
	$login = false;
 
}
 
?>
 

 
<ul class="topnav">
					echo "
if (isset($_SESSION['user_id'])){ 
 
}
 
?>
 

				}
if (isset($_SESSION['user_id'])){ 
if (isset($_SESSION['user_id'])){ 
				if ($navbar == "home"){
					echo "
if (isset($_SESSION['user_id'])){ 
	$login = true;
if (isset($_SESSION['user_id'])){ 
} else { 
 
?>
					";
				} else {
					echo "
if (isset($_SESSION['user_id'])){ 
	$login = false;
							<img src=\"/common/threadr/img/ThreadR_Home.svg\" alt=\"Home\"/>
 
?>
					";
				}
if (isset($_SESSION['user_id'])){ 
}
if (isset($_SESSION['user_id'])){ 
?>
if (isset($_SESSION['user_id'])){ 

if (isset($_SESSION['user_id'])){ 
<ul class="topnav">
		<?php 
	$login = true;
 
} else { 
						<a class=\"active\" href=\"%CONTENT_DIR%/news/\">News</a>
 

 
<ul class="topnav">
					echo "
	$login = true;
if (isset($_SESSION['user_id'])){ 
 

				}
if (isset($_SESSION['user_id'])){ 
}
if (isset($_SESSION['user_id'])){ 
?>
if (isset($_SESSION['user_id'])){ 

    <div class="dropdown">
		<button class="dropbtn">Boards</button>
		<div class="dropdown-content">
	$login = true;
}
	$login = true;
?>
	$login = true;

	$login = true;
<ul class="topnav">
} else { 
if (isset($_SESSION['user_id'])){ 
<ul class="topnav">
 
 
			if ($navbar == "about"){
 
} else { 
						<a class=\"active\" href=\"%CONTENT_DIR%/about/\">About</a>
 

 
<ul class="topnav">
					echo "
						<a href=\"%CONTENT_DIR%/about/\">About</a>
					";
if (isset($_SESSION['user_id'])){ 
 
if (isset($_SESSION['user_id'])){ 
}
		?>
	</li>
} else { 
} else { 
		<?php 
} else { 
	$login = false;
} else { 
}
					echo "
} else { 
?>
					";
 
<ul class="topnav">
					echo "
} else { 

 

if (isset($_SESSION['user_id'])){ 
 
if (isset($_SESSION['user_id'])){ 
}
		?>
	</li>
	<li class="right">
		<?php 
			if ($login) { 
} else { 
<ul class="topnav">
	$login = false;
				";
			} else { 
				if ($navbar == "login") {
 
} else { 
						<a class=\"active\" href=\"%CONTENT_DIR%/login/\">Log in</a>
					";
 
<ul class="topnav">
					echo "
	$login = false;
} else { 
 

if (isset($_SESSION['user_id'])){ 
 
			} 
		?>
	</li>
</ul>
<br />
+<?php
if (isset($_SESSION['user_id'])){
  $login = true;
} else {
  $login = false;
}
?>

<ul class="topnav">
}
if (isset($_SESSION['user_id'])){ 
}
	$login = true;
}
} else { 
}
	$login = false;
}
}
}
?>
}

}
<ul class="topnav">
?>
}
	$login = false;
?>
 
      } else {
?>
if (isset($_SESSION['user_id'])){ 
      }
?>
	$login = true;
?>
} else { 
?>
	$login = false;
?>
}
}
	$login = true;
?>
?>
?>

    } else {
?>
<ul class="topnav">
?>
	$login = true;
?>
} else { 
  </li>

 
    <button class="dropbtn">Boards</button>

	$login = true;

} else { 
      <a href="#">Board 2</a>

}

?>


  <li>
}
	$login = true;

<ul class="topnav">
<ul class="topnav">
?>
<ul class="topnav">
 
    }
?>
} else { 

<ul class="topnav">
if (isset($_SESSION['user_id'])){ 
}
	$login = true;
    if ($login) {
<ul class="topnav">
} else { 
<ul class="topnav">
	$login = false;
}
?>
        echo "<a href=\"%CONTENT_DIR%/profile/\">Profile</a>";
}
<ul class="topnav">
    }
?>
} else { 

<ul class="topnav">
if (isset($_SESSION['user_id'])){ 
}
	$login = true;
    if ($login) {
<ul class="topnav">
?>
?>
      if ($navbar == "login") {
        echo "<a class=\"active\" href=\"%CONTENT_DIR%/login/\">Log in</a>";
      } else {
 
}
<ul class="topnav">
    }
?>
} else { 
 
 
</li>
</ul>
<br />