Unity Build Automation may not support newly released Editor versions immediately because they require testing. Wait for availability, or use the nearest available patch version; differing versions may cause reimports or behavior changes.
Symptoms
- My builds are failing because the local Unity version isn't available on the Build Automation builders.
- My configuration is set to use the latest Unity Version, and my project has been updated, but Unity Build Automation still fails to use it.
Cause
When new versions of the Unity Editor are released, they must first undergo testing in Unity Build Automation before being made available on the service. Thus, even if the 'Always Use Latest <Unity Version>' option is selected, the version set locally in the project might not be available.
Resolution
New versions are typically added within a few days of release, so the simplest option is to wait and rebuild once the version appears in the dropdown.
Workaround, if you can't wait: Build with a version that's already available, either by turning off "Auto detect Unity version" and picking one manually, or by turning on "Build with closest version" (with the existing note about where it's unavailable). Note that building with a different version than your project's can cause asset reimports or behavior differences, so pick the nearest patch release in the same stream and test the result.
Please keep in mind that the 'Build with closest version' setting is disabled for projects using manual Git (SSH), encrypted UVC projects, or when no source control provider has been specified, because the project settings are inaccessible before checkout.
More Information
Build target configurations (creating a build target)