The Cristal Integration extension 1.5.0 has been released.
This version updates Cristal to version 1.2.0. This new Cristal version relies on recent XWiki APIs, and as such this extension no longer supports XWiki versions older than 18.2.0. On the other hand, thanks to these new APIs, the embedded Cristal instance now correctly displays the information of the current user, and the Cristal REST Server is no longer necessary (and will no longer be updated).
You can refer to Cristal's release notes for a more exhaustive list of changes.