Warning: require(D:\ftp\vendor\composer/ClassLoader.php): failed to open stream: No such file or directory in D:\ftp\vendor\composer\autoload_real.php on line 12

Fatal error: require(): Failed opening required 'D:\ftp\vendor\composer/ClassLoader.php' (include_path='.;C:\php\pear') in D:\ftp\vendor\composer\autoload_real.php on line 12