Fatal error: Uncaught exception 'Twig_Error_Loader' with message 'Unable to find template "profilefields/dropdown.html" (looked into: ./../adm/style).' in C:\xampp\htdocs\1258ext\vendor\twig\twig\lib\Twig\Loader\Filesystem.php:202 Stack trace: #0 C:\xampp\htdocs\1258ext\phpbb\template\twig\loader.php(103): Twig_Loader_Filesystem->findTemplate('profilefields/d...') #1 C:\xampp\htdocs\1258ext\vendor\twig\twig\lib\Twig\Loader\Filesystem.php(138): phpbb\template\twig\loader->findTemplate('profilefields/d...') #2 C:\xampp\htdocs\1258ext\vendor\twig\twig\lib\Twig\Environment.php(265): Twig_Loader_Filesystem->getCacheKey('profilefields/d...') #3 C:\xampp\htdocs\1258ext\vendor\twig\twig\lib\Twig\Environment.php(312): Twig_Environment->getTemplateClass('profilefields/d...', NULL) #4 C:\xampp\htdocs\1258ext\phpbb\template\twig\environment.php(147): Twig_Environment->loadTemplate('profilefields/d...', NULL) #5 C:\xampp\htdocs\1258ext\vendor\twig\twig\lib\Twig\Environment.php(288): phpbb\template\twig\environment->loadTemplate('profi in C:\xampp\htdocs\1258ext\vendor\twig\twig\lib\Twig\Loader\Filesystem.php on line 202

Solution
Copy the folder profilefields from prosilver/template/ to adm/style/