I had the same issue, I checked the bundles status and I figured out
this bundle "Adobe Experience Manager Core WCM Components Core Bundle
(com.adobe.cq.core.wcm.components.core)" was installed but not active
because of dependencies missing, I have an AEM 6.3 instance so I solved
this by installing AEM 6.3 Service Pack 2 (6.3.2.0) and AEM Comulative
Fix Pack.