Just update with the beta Rated 5 out of 5 stars

Just use the beta:

http://www.downloadhelper.net/install-beta.php?version=4.9.15a1

This review is for a previous version of the add-on (4.9.14.1-signed). 

Bug 519 and Hotfix Rated 5 out of 5 stars

I had the same problem, I couldn't since yesterday add Clips to my playlists.
The hotfix worked here and it seems actual that there are no other issues with youtube. Also Downloadhelper works together with other Add-Ons like Proxytube.
But at first there were some missing adjustemnts of Dowenloadhelper, don't know why. So I reinstalled Downloadfhelper after I had removed the Addon complete from Firefox.

This review is for a previous version of the add-on (4.9.14.1-signed).  This user has a previous review of this add-on.

Youtube Punishment: Phobia Rated 5 out of 5 stars

I changed my title to Phobia since the fix for dwhelper.yt-visitor-cookie worked.

My previous statement... Lately, the ability to comment, like , fav etc on Yotube went bye bye. A fix was to disable DownloadHelper. I hope it is just a fix and not The Fix. Otherwise have used DownloadHelper for years with good experience..

This review is for a previous version of the add-on (4.9.14.1-signed). 

Youtube Error: Cannot post comments Rated 2 out of 5 stars

Love this addon but currently it's causing an error when trying to post to youtube. Have to disable it to post comments.Please fix this guys, thx.

This review is for a previous version of the add-on (4.9.14.1-signed). 

DownloadH issue Rated 4 out of 5 stars

Was having problems adding to my playlists. Getting a YOUTUBE error message. So I started disabling addons one at a time till I found the culprit. It was DownloadH. I see in the comments that someone else is having the same type of issues.
I would post this in the support forum but that is dead for me.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Rated 5 out of 5 stars

Still going to give it 5 stars, I have no need for youtube comments, commenting is trash these days anyway. I can still download Youtube videos and am doing so right now. I hope the nice folks at Google and Youtube enjoy the taste of my salty balls and pubic hair.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Youtube issues Rated 3 out of 5 stars

For the past several days, I have not been able to comment or like videos on Youtube. After disabling this add-on, I can now do all of these things.

I hope an update is provided for this add-on that fixes these problems, as Download Helper was very useful for me! before these issues, it was a great add-on!

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Rated 4 out of 5 stars

Its a great extension, however, of the latest youtube updates and firefox updates.... YOU WILL NOT be able to leave comments, thumb up, subscribe or do a multitude of tasks on youtube. Very frustrating !!!

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Rated 5 out of 5 stars

Excelente, el complemento perfecto. Por ello uso exclusivamente mozzila firefox.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Rated 2 out of 5 stars

I agree to oynbzn!

Youtube post-button and vote-button does not work, when enabled DH.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

fatal error Rated 1 out of 5 stars

i found out that at ff21, youtube comment "post" button, "vote" buttons are suffering from vdh. hope you fix that soon.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Youtube blocks it! Rated 5 out of 5 stars

I give it a good score because it's not the program having problems, but YouPoop blocking it for some reason, you can't comment on video's, can't modify the new (and most boring) channel layout, can't add a channel trailer as well!

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Causes Error on Youtube Rated 3 out of 5 stars

I agree with the last 3 reviews that DownloadHelper is now causing problems with youtube, whereby errors are generated when posting comments or adding videos to playlists. I also agree that there needs to be an easy way to disable this extension (ie by clicking a button on the taskbar) so that it's easy to troubleshoot when these issues begin. I've had to completely disable DownloadHelper because of this now, which I would preferred not to have done, as re-enabling it to determine whether the issue is fixed is now not a simple button-click. Other than this, tho, amazing work. I will upgrade my rating to 5 once the bug has been fixed. Many thanks!

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Rated 3 out of 5 stars

if i open this addons ,when i change title of my youtube video, it will show "thInvalid request, authentication expired.",so i can't change the title

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

YouTube doing stupid **** again... Rated 1 out of 5 stars

YouTube is actively blocking users from using features on the site like commenting and subscribing unless I disable this addon. There needs to be a way to either disable this temporarily on the site without restarting Firefox, or write a bit of code that bypasses their anti-download scripts.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Nice but... Rated 5 out of 5 stars

...since today YouTube is blocking this Add-On. I can't change my video titles or can't like or can add favorites... i tested it with every Add-On but Video DownloadHelper is the only one is YouTube bugging around.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Workaround

We have a workaround for this issue and we need your help to verify it does not break other things in YouTube. Please check: http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=518

Rated 4 out of 5 stars

Have been using this for a while when im bored and looking for fun vids. not as good as it used to be but still good enough not to look for an alternative.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Rated 5 out of 5 stars

The people from firefox have really done a terrific job on this. I can download almost any video from any site with this, it's phenomenal. Downloading porn has never been easier! : D
Too bad I can't give you 5 billion stars for this instead of just 5.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Very helpful Rated 5 out of 5 stars

Works fine, does it's job properly, very helpful add-on.

This review is for a previous version of the add-on (4.9.14.1-signed). 

Rated 5 out of 5 stars

better than anything on chrome

This review is for a previous version of the add-on (4.9.14.1-signed).