Adding documentation so that this fix appears an important fix in the release notes and upgrade guide.

Author: gregorydlogan

docs/guides/admin/docs/releasenotes.md

@@ -1,5 +1,12 @@
 # Opencast 18: Release Notes
 
+## Opencast 18.next
+
+This release contains a fix for
+(Episode ID Roles)[https://docs.opencast.org/r/18.x/admin/#configuration/episode-id-roles/#episode-id-roles], which
+were broken in earlier 18.x releases.  Adopters affected by this issue should either reindex their search index or
+republish their recordings.  If you do not use episode id roles then this can safely be ignored.
+
 ## Opencast 18.5
 
 This release includes some minor fixes, as well as an improvement that makes the download of static files easier.[[#7213](https://github.com/opencast/opencast/pull/7213)]

docs/guides/admin/docs/upgrade.md

@@ -107,3 +107,8 @@ ACLs if you haven't used this feature before. **If this feature was already enab
 If it was not enabled before upgrading, you can start the rebuild by calling the `/index/rebuild/AssetManager/ACL` and
 `/index/rebuild/Search` endpoints. These endpoints will reindex the event ACLs in both the AssetManager index and the
 Search index. For more information, see [here](configuration/episode-id-roles.md).
+
+[[#7477](https://github.com/opencast/opencast/pull/7477)] a fix applied in 18.6 re-enabled
+(Episode ID Roles)[https://docs.opencast.org/r/18.x/admin/#configuration/episode-id-roles/#episode-id-roles].  If your
+site uses these roles, a reindex of the search index or republishing the affected events will resolve the issue.  This
+can be safely ignored if your site does not use episode id roles.