New Features
Promoted Search
Places included in search results
SEO improvement: Rich Google search results for forum pages
Updates to the message editor
Real-time virus scanner for file a...
Updated 6 months ago
Version 4.0
Blog Post
Wendy_S This is because we introduced SEO improvement: Rich Google search results for forum pages as given above in 18.12. Google updated the schema to include 1 more parameter (answerCount) as mandatory after 18.12 release and hence you see errors.
The parameter is added though, and it will reach you via release in 19.1.
Please note, the errors that are showing are only to highlight that Google is not able to show the rich snippet which are the rich results that were rolled into 18.12. This will have no effect on your community's SEO