what happened to the ability to download via mp4? all I'm seeing is the ability to download adp/mkv, and there the download stalls... ???

Videodownload works and did well for years. But now it converts the downloaded video without being asked to and then plants a fat QR code "watermark" in the top left corner if you don't buy the extension.

Ineterfejs to jest dramat, korzystanie z tego programu to droga przez mękę.
Video jakoś ściąga, ale trwa to strasznie długo, w darmowej wersji wideo jest słabej jakości i ma wstawiony wielki kod QR.

AFTER INSTALL. NO ICON SHOWS UP IN THE BROWSER???????

Requires a companion app for Youtube and puts a huge QR code on the videos needing to be converted.

It's paid software, don't install it, if you don't want to pay.

Well.... in short: On my Ubuntu machine (Ubuntu 22.04, Firefox 107.0.1 64bit) I get mostly errors on YouTube. Interestingly one download yesterday worked fine - but it was the only one.
The downloadable files are listed, but... as mentioned: VideoDownload Helper says: Data may be corrupt - and refuses download. Only those videos are downloadable, which - anyway - can be downloaded using "download media" from Firefox directly. And this isn't the sense of the addon, because such downloads are simple to manage without addon.
Edit:
This is strange:
ffprobe version n4.1.5-vdhcoapp Copyright (c) 2007-2020 the FFmpeg developers
built with gcc 9 (Ubuntu 9.3.0-17ubuntu1~20.04)
configuration: --arch=x86_64 --prefix=/home/mig/git/vdhcoapp/converter/src-build/linux/64/converter-build --extra-version='"vdhcoapp"' --extra-cflags='"-I/home/mig/git/vdhcoapp/converter/src-build/linux/64/deps/include"' --pkg-config=pkg-config --pkgconfigdir=/home/mig/git/vdhcoapp/converter/src-build/linux/64/deps/lib/pkgconfig --extra-libs='"-ldl"' --enable-shared --enable-gpl --enable-libmp3lame --enable-libopenjpeg --enable-libopus --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx265 --enable-libxvid --enable-libx264 --enable-libaom --enable-avresample --disable-indev=sndio --disable-outdev=sndio --disable-doc --disable-ffplay --extra-ldflags='-L/home/mig/git/vdhcoapp/converter/src-build/linux/64/deps/lib -L/home/mig/git/vdhcoapp/converter/src-build/linux/64/zlib'
WARNING: library configuration mismatch

This WARNING irritates me - any idea?

Beware: Works only occasionally - but usually requires a "companion app" that Apple won't let it download because developer "has not had it checked for malicious software."

This works for a while but later will ask to install the Companion App.

Stopped working on youtube

It's mostly good when it works, which has been most of the time. JDownloader and Open Video Downloader seem to cover its gaps fine.

I have a minor issue and a major issue, though, causing this two star review.

First, the minor issue is that the "support site"/"forums" is a Google Groups conversation, except that's been blocked (by Google?) with a "Banned content warning". "Video DownloadHelper Q&A has been identified as containing spam, malware, or other malicious content." So you guys are getting this ugly feedback/"bug report" here.

Second, the major issue, for whatever reason, I'm pretty sure this plugin has been causing me major, major memory management issues in Firefox, especially with Twitch open. Basically, I leave a Twitch stream open for several hours (let's say 4+), close the tab, and the entire browser locks up for up to a minute (non-responsive program). I experience similar issues opening some media tabs during long and heavy browsing sessions without closing the browser.

This has also caused GPU driver crashes (AMD and nVidia) + crashing Discord, Hydrus, Path of Exile, Windows Explorer. Your extension is doing this! I don't know if it's a combination with something else, but I think this is the cause. This has been going on for years, across three graphics cards (AMD 290X, nVidia 970, nVidia 3070). The newer GPUs have been more resilient but that's only treating a symptom.

I have checked my computer with multiple memory management apps looking for anything that stands out: Task Manager (Processes and Performance), Resource Monitor, ProcessExplorer, RAMMap, Poolmon. I found some minor oddities that I've done my best to address, but the problem wasn't fixed. No issue in Chrome (does not have Video DownloadHelper). I tested Firefox on a clean profile with no issue. I started a new Firefox profile, but manually restored many parts of my old profile (dirty restore) with all my old extensions and the problem came back. I turned off half my extensions including this one, and the problem went away (for a few blissful months). I've since turned on a few of those extensions separately with no issue. Last night I turned on this extension too, and the problem is finally back.

As of typing this, I have one Twitch tab open right now. This browser session has been going for 12-24 hours, let's say. I check Video DownloadHelper's button in the Twitch tab. VDH is showing me 40 things I can download. 40! Most are streams, but I've only visited maybe 5 channels this entire browsing session. VDH shows multiple quality options for streams with transcoding, as it should. Some of these options are from tabs I closed hours ago. Some streamer avatars are mismatched. This can't be right.

I'm going to turn off your extension now. If I'm wrong I'll delete this report. I'm so tired of this.

First I tried downloading a video to an mkv file. The download seemed to go okay until "aggregation", which had my old laptop on its knees (20% done after working all night).

Then I tried downloading an MP4. No conversion needed, so it should be great, right? NO SOUND.

Goodbye Video DownloadHelper!

Extension not working in Ubuntu 22.04
Companion app not working...

Doesn't allow me to download only and not convert. As i will do the conversion manually myself with hardware acceleration later.