If the error persists even after these fixes, check your Log files (Help -> Create a Log) and post them on the JDownloader community forums; the developers are remarkably active in helping users diagnose specific memory leaks.
Unlike a typical crash, this error usually indicates that the —the engine JDownloader runs on—has hit its pre-assigned memory limit. Even if your PC has 32GB of RAM, JDownloader might only be allowed to use a tiny fraction of it. jdownloader the download system is out of memory
Navigate to your JDownloader installation folder (usually C:\Users\YourName\AppData\Local\JDownloader 2.0 ). If the error persists even after these fixes,