Write a comment below (if on a forum) or go to web.archive.org and paste the link to find cached versions. Alternatively, request the file on the Wanbo subreddit r/Wanbo.
If your projector is already running a stable version, you can check for official updates through the menu. Navigate to Settings : Use your remote to tap the button and select the gear icon ( ) in the top right corner. Check for Updates Device Preferences System Update
Press the button on the remote and select the Settings icon. Navigate to Device Preferences > About . Click on System Update .