Undefined variable $taxonomy

(1/1) ErrorException

Undefined variable $taxonomy

in PublicationsSlider.php line 77
at RegisterExceptionHandler->handleError()in PublicationsSlider.php line 77
at PublicationsSlider->setFields()in PublicationsSlider.php line 29
at PublicationsSlider->handle()in PublicationsSlider.php line 15
at PublicationsSlider->__construct()in FlexibileConverter.php line 72
at FlexibileConverter->fieldConvert()in FlexibileConverter.php line 52
at FlexibileConverter->convertFields()in FlexibileConverter.php line 35
at FlexibileConverter->convert()in page.php line 30
at PageController->handle()
at call_user_func_array()in Invoker.php line 74
at Invoker->call()in WordPressControllersServiceProvider.php line 87
at WordPressControllersServiceProvider->Rareloop\Lumberjack\Providers\{closure}()in Dispatcher.php line 114
at Dispatcher->mindplay\middleman\{closure}()
at call_user_func()in Delegate.php line 38
at Delegate->handle()in Dispatcher.php line 59
at Dispatcher->handle()in Dispatcher.php line 75
at Dispatcher->dispatch()in WordPressControllersServiceProvider.php line 92
at WordPressControllersServiceProvider->handleRequest()in WordPressControllersServiceProvider.php line 35
at WordPressControllersServiceProvider->handleTemplateInclude()in class-wp-hook.php line 324
at WP_Hook->apply_filters()in plugin.php line 205
at apply_filters()in template-loader.php line 104
at require_once('/home/olsztyn/domains/olsztyn.pan.pl/public_html/web/wp/wp-includes/template-loader.php')in wp-blog-header.php line 19
at require('/home/olsztyn/domains/olsztyn.pan.pl/public_html/web/wp/wp-blog-header.php')in index.php line 7