Parse error: syntax error, unexpected 'else' (T_ELSE), expecting end of file-where is the error?

Question

I want to create a login-form with php and html. But there is an error in one php-file.

I´m running the Database on XAMPP and test it just offline on my PC.

When i run this code, i get this error message: "Parse error: syntax error, unexpected 'else' (T_ELSE), expecting end of file in *** on line 54".

Here is line 54 to end:

      }else {
        header("Location: ../signup.php?");
        exit();
        }

Here is the full code:

<?php
if (isset($_POST['signup-submit'])) {
  require 'dbh.inc.php';
  $username = $_POST['uid'];
  $email = $_POST['mail'];
  $password = $_POST['pwd'];
  $passwordRepeat = $_POST['pwd-repeat'];
  if (empty($username) ||  empty($email) || empty($password) ||  empty($passwordRepeat)) {
    header("Location: ../signup.php?error=emptyfields&uid=".$username."&mail=".$email);
    exit();
  } else if (!filter_var($email, FILTER_VALIDATE_EMAIL) && !preg_match("/^[a-zA-Z0-9]*$/", $username)) {
    header("Location: ../signup.php?error=invalidmailuid");
    exit();
  } else if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
    header("Location: ../signup.php?error=invalidmail&uid=".$username);
    exit();
  } else if (!preg_match("/^[a-zA-Z0-9]*$/", $username)) {
    header("Location: ../signup.php?error=invaliduid&mail=".$email);
    exit();
  } else if ($password !== $passwordRepeat) {
    header("Location: ../signup.php?error=passwordcheck&uid=".$username."&mail=".$email);
    exit();
  } else {
    $sql = "SELECT uidUsers FROM users WHERE uidUsers=?";
    $stmt = mysqli_stmt_init($conn);
    if (!mysqli_stmt_prepare($stmt, $sql)) {
      header("Location: ../signup.php?error=sqlerror");
      exit();
    }
  }
}  else {
    mysqli_stmt_bind_param($stmt, "s", $username, );
    mysqli_stmt_execute($stmt);
    mysqli_stmt_store_results($stmt);
    $resultCheck  = myssqli_stmt_num_rows($stmt);
    if ($resultCheck > 0) {
      header("Location: ../signup.php?error=usertaken&mail=".$email);
      exit();
    } else {
        $sql = "INSERT INTO users (uidUsers, emailUsers, pwdUsers) VALUES (?, ?, ?)";
        $stmt = mysqli_stmt_init($conn);
        if (!mysqli_stmt_prepare($stmt, $sql)) {
          header("Location: ../signup.php?error=sqlerror");
          exit();
        } else {
        $hashedPwd = password_hash($password, PASSWORD_DEFAULT);
        mysqli_stmt_bind_param($stmt, "sss", $username, $email, $hashedPwd);
        mysqli_stmt_execute($stmt);
        header("Location: ../signup.php?signup=succes");
        exit();
        }
      } mysqli_stmt_close($stmt);
        mysqli_close($conn);
      }else {
        header("Location: ../signup.php?");
        exit();
        }

So where is the error? I closed everything correctly i think.