I'm using DXA 2.0 GA with Sdl Web 8.5. At this stage, all I have is the out-of-the-box demo application, which I have not customised or added to. When I start it up and attempt to access the home page I get this error:
21:20:22.741 [http-nio-80-exec-3] INFO c.s.d.t.m.impl.DefaultModelBuilder - Page Model is null, for model data id = 247 21:20:22.749 [http-nio-80-exec-3] ERROR c.s.w.c.controller.PageController - Exception while processing request for: /dxa-webapp/ java.lang.IllegalArgumentException: Page Model is null after model pipeline, model builder are not set?
A little earlier, I'm getting these warnings:
21:20:22.741 [http-nio-80-exec-3] WARN c.s.d.t.m.impl.DefaultModelBuilder - Exception happened while creating a page model 247 com.sdl.webapp.common.api.mapping.semantic.SemanticMappingException: Cannot create entity because entity class is null, have you added all modules you need?
21:20:22.727 [http-nio-80-exec-3] WARN c.s.d.t.m.impl.DefaultModelBuilder - Cannot do a semantic mapping for class 'null', model data 'PageModelData(id=247, structureGroupId=4, meta={og:type=article, twitter:card=summary, og:title=Home, og:locale=en-US, description=Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut semper ex tortor, a ullamcorper sem venenatis sed. In interdum leo eu orci pharetra luctus. Nulla ut blandit urna, ac maximus mauris., sitemapKeyword=000 Home, og:description=Lorem ipsum dolor sit amet, consectetur adipiscing elit. Ut semper ex tortor, a ullamcorper sem venenatis sed. In interdum leo eu orci pharetra luctus. Nulla ut blandit urna, ac maximus mauris.}, pageTemplate=PageTemplateData(id=55, title=Home Page, fileExtension=html, revisionDate=2018-04-21T17:35:12.540Z, metadata={view=GeneralPage, includes=ListWrapper(values=[system/include/header, system/include/footer])}), title=Home, regions=[RegionModelData(name=Hero, includePageId=null, entities=[EntityModelData(id=277, componentTemplate=ComponentTemplateData(id=196, title=Carousel [Hero], revisionDate=2018-04-21T17:35:28.290Z, outputFormat=HTML Fragment, metadata={view=Carousel, regionView=Hero}), linkUrl=/, content={itemListElement=ListWrapper(values=[{link={linkText=Discover More, internalLink=EntityModelData(id=274, componentTemplate=null, linkUrl=/further-information, content={image=EntityModelData(id=273, componentTemplate=null, linkUrl=, content=null, binaryContent=null, externalContent=null), articleBody={content=RichTextData(fragments=[
I am aware that DXA is sometimes a bit fussy about having everything published, so I've made a point of double-checking that everything is. Perhaps there's something else I've missed?
What can cause the Model to be null in this situation? It seems likely that the warnings are also relevant. Under what circumstances would I need to add modules?