It seems that there is a memory problem. A restart of JDownloader is required to fix the problem. If even 2 restarts do not fix it, please visit our support chat.
Do you see this message oftenly? Try this:
- Go to the menu JDownloader > About JDownloader. You will see somewhere something like: Memory: Usage: 40 MB – Allocated: 44 MB – Max: 64 MB. This means that JDownloader is being launched with a max heap of 64 MB. Increasing this limit may fix your memory issues.
- Quit JDownloader.
- Right-click JDownloader’s icon in the Finder, then choose “Show Package Contents” in the context menu.
- Open the folder called “Contents”.
- Open the file called “vmoptions.txt”. If this file doesn’t exist, create it yourself using a plain text editor.
- Add the following:
-Xmx256m
This will increase the max memory to 256 MB. Some people add up to 512 or 1024 MB, but first let’s see if 256 is good enough.
Launch JDownloader, go again to the About JDownloader window and see if the Max field in the Memory section was correctly increased.
Julio Sancho's Blog 