I have the same issue, running UniServer Zero XI 11.6.1 I get the following error in the apache error.log file when running as a service: PHP Warning: PHP Startup: Unable to load dynamic library 'C:/UniServerZ/core/php54/extensions\\php_ldap.dll' - The specified module could not be found.\r\n in Unknown on line 0 This does NOT happen when running as an app. 2 questions, 1] Why the mixed slashes (fwd & backwd), and 2] Is this likely a system/windows path issue? EDIT: Resolved: http://superuser.com/questions/588426/apache-php-ldap-dll-error Copied three noted dlls into windows\system folder and issue went away, not ideal but usable.