Version 10.7 (Download Page)
Critical update: For users of 10.3 and below
Update recommended?: Yes, for all users.
Support for existing projects: Yes, all projects saved with 7.x and greater are supported by this version.
Changes Made: See the Change Log
With your current version installed, click the 'Check for Updates' option in the Launchpad and when it finds the new version, choose to download & install it. (alternately, you can manually download from this website). Your current installed version will be detected and will be updated to the new version. After install, to update your actual existing projects to fully use the new version, for each project that you want to update, just open it for editing and then save it (and re-create any distributions, etc.).
Note: These instructions are only for downgrading from a 10.x version to an earlier 10.x version. Follow these instructions carefully. First, before starting, you should back up your existing Projects folder to a safe location as a precaution. This is ultra-easy to do by clicking the Settings link in the Launchpad. Make note of the Projects folder that shows and then click the "Project Backup / Transfer to ZIP" button. By default it should already be set to back up all of your projects to a ZIP file on your Desktop - just go ahead and have it do that (it may take awhile). Once you've done that, you need to uninstall your existing SSE Setup version BUT - and this is IMPORTANT - during the uninstall, if you are asked to keep remaining files/folders or delete them, you want to KEEP them! Once the uninstall has completed, install the older version. Your projects should still exist and appear (if not, make sure the Projects location as shown in the Settings link in the Launchpad is correct). Then simply open any projects where you want to use the old version and re-save them and re-create your distribution(s) for them.