It used to be you could choose what was blocked and what was let through, now its seems the app chooses. I don't need an app i can't control

Unfortunately breaks too many sites, used to be my app of choice to toggle flash if needed but as an example installed and running interaction between flashblock and WhatsApp web lock Firefox up solid and the whole machine becomes very very unresponsive, if you can get a terminal open it's possible to kill FF otherwise it's a full on restart.

I realise it may not be the fault of the app but I had to choose which to keep

I liked this product a LOT more when it was less obtrusive. At first it just put an icon up to tell you that it had blocked something in flash. Then it started putting little buttons at the top of the page. Now it goes full screen to tell me that it's active. STOP THAT!!! Go back to the icons and GET OUT OF MY FACE!

If there was a way to give this add on zero stars, I would. Not that it doesn't work, because it does. But... I noticed that, if for example you want to block ANY KIND of flash on ALL websites, this applications seems to know better than you do. So, if after a while you take a peek at the listing of sites that are allowed to run flash, and... surprise, surprise, look what is there; all the URLs you removed previously! Now, I can understand that some people would like this to work without fiddling on FB, YT, G00gle or any other web rubbish. And they're welcome to it. But call me crazy... If I define MY settings on MY device, to follow MY preferences, I kind of resent an app telling me they know better, and I should STFU... If I wanted that I'd use other rubbish applications like AdBlock with its "Acceptable Ads", right? Ah well... [REMOVE] > Click

This addon break page formatting by its message about blocked content.

Lots of trouble lately with videos autoplaying. Enabling flash by site instead of by specific video clicked on means messes like I just encountered with FOUR videos on one page, from the same source, all starting to play simultaneously once flash is enabled for their source site--and they won't stay PAUSED even if I pause 3 to keep one playing in splendid audio isolation, but keep breaking into play after 30 seconds or so. VERY BAD.

FF63.0b8; Mac OS High Sierra, up to date, also running NoScripts 10.1.9.6.

Nie działa , nie blokuje automatycznych filmów

All of you complaining that it doesn't work at all and lets video through need to take another look at the name of the extension. It's FLASH block not Video block.

By default Youtube and most other major cites use html5 video now so blocking flash does nothing. Indeed, you now have to approve flash for it to run on a website. Doesn't mean it's not useful to control flash more granularity but don't diss an extension because it doesn't do something it was never designed to do.

If you want videos to be blocked you can try something like: https://addons.mozilla.org/en-US/firefox/addon/image-video-block/?src=search

Works well on a lot of sites, though it's not blocking everything related to Flash, as one can see here:
http://get.adobe.com/flashplayer/about/
Users complaining that it's not working at all should know that many videos don't use Flash anymore, but HTML5, and this addon is not designed to block HTML5 content.
https://www.w3schools.com/html/html5_video.asp

The vast majority of videos play like it's not even installed. Practically useless.