"Download with JDownloader" extension now has issues with Package Name not being set correctly, as confirmed by JDownloader Manager's developer Jiaz.
(NOTE: See "USER TIP" at bottom for how to best use via right click instead of download intercept for better compatibility).
Though this extension is much better than others (including official My JDownloader extension), and it actually intercepting downloads automatically (to a degree), because it in part, no longer working

For the extension developers, you can contact JDownloader Manager (the app, not the extension) support at https://support.jdownloader.org/Tickets/Submit, to confirm or get details regarding this issue and how metadata is now supposed to be passed to JDownloader.

It now doesn't send Package Name (referring page title) to JDownloader, resulting in JDownloader packagizer rules failing or resulting in "mp4" as entire file name (since only have package name generated from filename, which doesn't even occur until after Packagizer rules run), even when have Even occurs with Send Cookies enabled.
Anything needed in Arguments extension settings field? Shows as empty.
Issue confirmed by developer of JDownloader, Jiaz, in support ticket (can contact him at https://support.jdownloader.org/Tickets/Submit).
Using with Waterfox v56.2.1 (64-bit) with Windows 10 Pro 64-bit with "Download with JDownloader" extension v0.1.5.
Also, have to right click > Download with JDownloader (vs. using download intercepting) very often to get correct file name or referring page set, though even then Package name isn't set in time any longer.
Though Package Name does show up as non-empty in JDownloader when using this extension in all cases, that is misleading since its actually just generated from file name with _ replaced with spaces, which happens to late for it to get used by packagizer rules.
This is an incredible extension, much better than any other alternative, especially with download intercepting, so please fix.

Thanks,
Dan

___
USER TIP:
Often I need to right click on download link > Download with JDownloader in order to get any metadata (referring page URL, package name, etc.) sent to JDownloader. as is needed to get packagizer rules to run to rename the download or for premium plugin support.
However, as mentioned, that seems broken at least when comes to setting Package Name.
Though Package Name does show up as non-empty in JDownloader when using this extension in all cases, that is misleading since its actually just generated from file name with _ replaced with spaces, which happens to late for it to get used by packagizer rules.