- Embedded forums are deprecated.
- SPAM management (at site and blog level) is gone as are SPAM-and-application-specific email templates. Instead, the abuse core service (which already has notifications and workflow) is used for SPAM as well as community-driven abuse.
- Added support for Java 8 with Solr 4.10.1 requirement since Java 7 EOLs in April 2015.
- Support for IE8 and IE9 has been dropped. Support for IE10 drops to "tier 2". See Supported software versions for servers, applications, and browsers
- The Forum Thread Suggested Answer Notifications plugin is deprecated. It is replaced by the Forum Reply Suggested Answer Email Plugin.
- Custom content pages can no longer be copied using the Copy button. They can, however, be exported or imported.
- Moderation notes are not part of the new moderation, abuse and spam system.
- The administrators group and the deleted posts forum have been removed.
- Support for legacy IFileViewers (not plugin based) and registration of file viewers is deprecated to be removed in the next major release.
- Support for legacy file-based email templates (ex. \languages\en-us\emails) is deprecated to be removed in the next major release