Dummy Content's create, Fetch links doesn't work

[yasuflatland-lf]

steps to reproduce

1. Navigate to Web Content Article
2. Select Select create contents type
3. Input Amount of links in the generated contents
4. Press Fetch links

combo?browserId=chrome&minifierType=js&languageId=en_US&b=7310&t=1605502757996&/o/frontend-js-jquery-web/jquery/jquery.min.js&/o/frontend-js-jquery-web/jquery/init.js&/o/frontend-js-jquery-web/jquery/ajax.js&/o/frontend-js-jquery-web/jquery/bootstrap.bundle.min.js&/o/frontend-js-jquery-web/jquery/collapsible_search.js&/o/frontend-js-jquery-web/jquery/fm.js&/o/frontend-js-jquery-web/jquery/form.js&/o/frontend-js-jquery-web/jquery/popper.min.js&/o/frontend-js-jquery-web/jquery/side_navigation.js:2 POST http://localhost:8080/group/control_panel/manage?p_p_id=com_liferay_support_tools_portlet_LiferayDummyFactoryPortlet&p_p_lifecycle=2&p_p_state=maximized&p_p_mode=view&p_p_resource_id=%2Fldf%2Fimage%2Flist&p_p_cacheability=cacheLevelPage&_com_liferay_support_tools_portlet_LiferayDummyFactoryPortlet_redirect=http%3A%2F%2Flocalhost%3A8080%2Fgroup%2Fcontrol_panel%2Fmanage%3Fp_p_id%3Dcom_liferay_support_tools_portlet_LiferayDummyFactoryPortlet%26p_p_lifecycle%3D0%26p_p_state%3Dmaximized%26p_p_mode%3Dview&_com_liferay_support_tools_portlet_LiferayDummyFactoryPortlet_mode=WCM&_com_liferay_support_tools_portlet_LiferayDummyFactoryPortlet_mvcRenderCommandName=%2Fldf%2Fcommon&_com_liferay_support_tools_portlet_LiferayDummyFactoryPortlet_formDate=1605510025030 500