We are committed to supporting the current major version of SketchUp products, in addition to the two most recent major previous versions. We call this our "Current Minus Two" policy. If you are on a version which is more than two versions older than the current version, some services may not be available.
For example, if SketchUp 2021 is the current major version of SketchUp, the versions that are supported are 2021, 2020 and 2019.
In keeping with this policy, 3D Warehouse content is available in the current version and the two versions prior to it. When a new SketchUp version is released, the files for the oldest supported versions will be removed. A Collada (DAE) version of the uploaded model is also always available for all users to download, however, the original uploaded version is available only to the original uploader.
For example, If a file was originally uploaded from 2016 then the formats on 3D Warehouse would be 2021, 2020, 2019 and Collada. The 2016 file would be available for download only by the user who uploaded it.