You need refresh this addon.

— 1.14.0 doesn't work with your Cyberfox/Firefox 52.3.0?

— just install 1.13.8.
https://addons.mozilla.org/firefox/downloads/file/685614/ublock_origin-1.13.8-an+fx+sm+tb.xpi

More: https://github.com/gorhill/uBlock/wiki/Firefox-WebExtensions

uBlock 1.14.0 is not working under Firefox version 52.3.0 ESR. is there a fix for this or how do I downgrade to a previous working version? thanks!

Very bad, the last version is installed as an automatic update on Firefox 52 ESR but, as it is not compatible, it is immediately disabled. The addon should not install on not compatible Firefox, unexperienced users could not be able to manage this situation.
Five stars anyway.

Best way to block ads..Thx to Developers

Seit der Version 55.03 von Firefox verschwindet UBlock aus der Toolbar und funktioniert auch nicht mehr. De/installieren bringt nur kurzfristig was , dann das selbe Problem wieder. Bitte beheben.

Just perfect!

The only Ad blocker you should ever use.

Nareszcie wsparcie dla FF 57+ :D
aż nie mogłem uwierzyć jak to zobaczyłem

I have used this extension for a very long time, works amazingly is very light weight

FF 55.0.2 for Android uBlock Origin/webext-hybrid 1.13.10

Last PC version works with issues: does not block some ads, ex. freaking video ads on Youtube.
FF 55.0.3 for Linux uBlock Origin/webext-hybrid 1.13.10
Hope, you fix this bugs soon!

Works great

UBlock Origin is now Firefox 57 friendly & is the number 1 add on for taking Firefox forward. Low on memory usage & high on results it is for me at least, the only blocker you need. Many thanks to the developer for a great add on