Can't find extension class for "SS_MinifiedResponseExtension"

[meenkshi]

ERROR [Emergency]: Uncaught InvalidArgumentException: Object::add_extension() - Can't find extension class for "SS_MinifiedResponseExtension" IN GET /ss/ Line 186 in E:\xampp\htdocs\ss\vendor\silverstripe\framework\src\Core\Extensible.php Source ====== 177: $class = get_called_class(); 178: $extension = $classOrExtension; 179: } 180: 181: if (!preg_match('/^([^(]*)/', $extension, $matches)) { 182: return false; 183: } 184: $extensionClass = $matches[1]; 185: if (!class_exists($extensionClass)) { * 186: throw new InvalidArgumentException(sprintf( 187: 'Object::add_extension() - Can't find extension class for "%s"', 188: $extensionClass 189: )); 190: } 191: 192: if (!is_subclass_of($extensionClass, Extension::class)) { Trace ===== SilverStripe\View\ViewableData::add_extension(SS_MinifiedResponseExtension) _config.php:10 require_once(E:\xampp\htdocs\ss\app_config.php) Module.php:289 SilverStripe\Core\Manifest\requireFile(E:\xampp\htdocs\ss\app/_config.php) Module.php:187 SilverStripe\Core\Manifest\Module->activate() ModuleManifest.php:153 SilverStripe\Core\Manifest\ModuleManifest->activateConfig() CoreKernel.php:213 SilverStripe\Core\CoreKernel->bootConfigs() CoreKernel.php:197 SilverStripe\Core\CoreKernel->boot() HTTPApplication.php:135 SilverStripe\Control\HTTPApplication->SilverStripe\Control{closure}(SilverStripe\Control\HTTPRequest) HTTPMiddlewareAware.php:65 SilverStripe\Control\HTTPApplication->callMiddleware(SilverStripe\Control\HTTPRequest, Closure) HTTPApplication.php:137 SilverStripe\Control\HTTPApplication->execute(SilverStripe\Control\HTTPRequest, Closure, ) HTTPApplication.php:116 SilverStripe\Control\HTTPApplication->handle(SilverStripe\Control\HTTPRequest) index.php:24

/app/_config.php
Member::add_extension(SS_MinifiedResponseExtension::class);

/app/extantion/SS_MinifiedResponseExtension.php
/app/extantion/SS_MinifiedResponse.php