Hi! With the release of Unity 2021.1, DOTS is at a crossroads in terms of compatibility with the currently available Unity versions. While certain parts of the DOTS ecosystem (Burst, Jobs, Math, Collections) are compatible with the 2021.1 TECH stream, other packages such as the entire entities suite is not. For your projects there are now two upgrade scenarios depending on your use of DOTS packages. Scenario A - My project is not using entities based packages You will find that the Burst package and its accompanying packages are visible and present in the package management system, and you can continue to upgrade into the 2021 tech stream of updates. Scenario B - My project is using entities based packages You must stay on Unity 2020 LTS and on Entities 0.17 for now. Future releases of Entities will not be compatible with Unity 2021 until the end of the year at the earliest. Upgrading to 2021.1 and using current or future Entities packages will not work and is not expected to work. As soon as we can, we will provide further information on how we will continue to develop and release Entities and Unity in lock step to provide a faster path of releasing DOTS to the Unity community. I will leave the thread open for questions, but please understand that this is the information we can share at this point in time.