Hi

As a first step, I recomend opening the Google Play app on your device and making sure that Firefox for Android is up to date. Assuming it is, you should be able to install that add-on from here.

Yes i updated it. Again, video speed controller firefox addon for android cannot be re-installed.

Okay

I think you may need to open the Android Settings app (typically a cogwheel icon), select Applications and find Firefox.

You should see the option to Clear Cache - select this (do not Clear Data)

Now try to install the add-on again, does it work?

That didn't work. Other add-ons work except video speed controller for android. Again, I cannot re-download video speed controller android firefox add-on after having deleted it a week ago when the community pointed out the disabled add-ons which apparently were fixed this Monday.

If other add-ons are working fine and it is just this one, it may be a problem with this add-on.

Add-ons are developed and supported by their independent developers. I recommend that you contact the developer of this add-on directly about this issue through the support link on the page you downloaded the add-on from.

It's strange the dev hasn't fixed the bug yet as I'm sure the person received several reports by now from the community. Thanks anyways.

No problem, fingers crossed this will be resolved soon.