Always download JDownloader 2 from the official source at jdownloader.org to avoid bundled adware, recommends VideoProc.
Right-click the package and select "Start Download" or click the "Play" icon in the top left to move the link from LinkGrabber to the Download tab. 4. Advanced Features >JDownloader 2 LINK<
The core of JD2 is the tab, which processes links before downloading. Always download JDownloader 2 from the official source