Regarding the termination of Enlighten support by Unity Technologies

As reported within the official blogs, social media accounts, and forum of Unity Technologies, the implementation of Enlighten global illumination within the Unity game engine has been officially announced for cease of support and removal.

This removal of Enlighten from Unity 2021.1 is the result of the conditions of the license agreement between Unity Technologies and Geomerics Ltd. (a wholly owned subsidiary of ARM Ltd.) and has no bearing on the existence and or continuation of development of Enlighten as a product.

In May of 2017, Silicon Studio Corporation acquired all worldwide rights to develop, support, license, market and sell Enlighten from Geomerics Ltd. From point of acquisition Silicon Studio has established a new Enlighten development and business team that has continued the work begun by the technology creators, creating new features and advancements to the technology, providing licensing and development support to clients worldwide, as well as taken steps to create new technologies through integration with other Silicon Studio software.

Developers affected by the removal and interested in exploring new development platforms are welcome to contact the Enlighten team for consultation on available solutions.

Official announcement of acquisition of Enlighten rights by Silicon Studio (May 10th, 2017)
https://www.siliconstudio.co.jp/en/news/pressreleases/2017/en1705enlighten/en1705enlighten.html

Enlighten Global Illumination official website
https://www.siliconstudio.co.jp/middleware/enlighten/en/