The IDE extension retrieves the Analyzer RPC component from https://developers.redhat.com/content-gateway/rest/browse/pub/mta/8.0.0
This has proven to be problematic in some organizations with restricted network access. There is a possibility of downloading this component separately and configuring the extension to use it. That would enable a corporate approach where the Analyzer RPC is downloaded by a central team, and served internally from a different location.
None of this is documented, neither the fact that the IDE extension downloads an additional component, nor how to configure the extension when that download fails.