1) open your browser's "Add-ons and themes" page (using the URL: "about:addons" - or by navigating via the menu)
2) click on the demo version of "HLS Video Download" (that you installed previously)
3) click on the "Options" tab: there is a purple button that will guide you through the purchase and automatically upgrade the demo version to the full version

This plugin takes the approach of implementing the most *commonly used* HLS features - but to not provide every exotic HLS special case in advance. (I think that most users are better served with an inexpensive plugin that covers the most relevant HLS features than with the alternative of having a 100% HLS feature complete plugin that would be much more expensive.)

Therefore I can only repeat myself: Before buying the plugin you should use the free demo version to verify if the plugin correctly downloads a *playable* version of the specific stream that you are interested in.

The stream that this user was trying to download uses AES-128 media encryption. This is a rarely used HLS feature that I currently consider to be rather irrelevant (this is the first incidence of a user actually requesting it) and which therefore is indeed NOT currently implemented in this plugin. (If there was some substantial user feedback requesting a respective enhancement, this feature might be added in a future plugin version. By all means: If you find that the demo version does not work for some stream that you are specifically interested in, drop me a line to add some weight to a respective feature request!)

Regarding download speed: This plugin sequentially downloads all the chunks of a respective media stream. This approach was selected for its robustness, as servers might actually detect and block unusual parallel download activity. I imagine that other downloaders using a parallel approach might be faster in certain scenarios, e.g. if the server allows parallel chunk downloads and if it imposes bandwidth limitations for individual files - provided that the user's internet connection is not the limiting factor anyway.


Update 26-12-2021: The new 1.1.0 release of the plugin now supports decryption of AES-128 encrypted HLS streams.

I am glad that the plugin meets your expectations ! Nothing like a happy customer :-)

PS: I encourage other people to also leave meaningful review comments to allow readers to distinguish actual experience reports from malicious down voting from persons that probably never even used the plugin or maybe expected to use it for a scenario that the plugin just isn't designed for (see below "review").

If somebody is unhappy with the plugin he should have the courtesy to add some description of why he is unhappy. This will allow readers to assess the relevance of the criticism and it might even provide valuable feedback to improve future versions of the plugin.