I am seeing below error in model service log. And 404 received on the website for all pages. Let me know what I am missing in configuration.
2018-07-12 04:19:46,118 WARN c.s.d.m.s.p.e.PageModelExpander - Cannot expand entity EntityModelData(id=257-99, componentTemplate=null, linkUrl=null, content=null, binaryContent=null, externalContent=null) for page PageRequestDto(publicationId=5, uriType=tcm, path=/error-404, includePages=INCLUDE, contentType=MODEL, dataModelType=R2, expansionDepth=100, depthCounter=com.sdl.dxa.common.dto.DepthCounter@98) com.sdl.webapp.common.exceptions.DxaItemNotFoundException: Cannot find a CP for componentUri = tcm:5-257, template id = 99
Also, I see DXA settings in Admin screen greyed out.