It causes a lot of websites to stop working altogether

This was working great until I just updated Firefox to v 90.0.2 (64-bit). Now, if I have uMatrix enabled, none of my browser pages display. If I disable it, they do display.

Best addon!

Many thanks to the developer for continuing the support for this extension, I am using it in most of my browsers as I want to decide site by site what to permit and what to block (I couldn't find a way to do this with uBlock or NoScript, though I am or was using these as well.

It doesn't support Firefox on Android

UI is messy and colorblind-unfriendly. Breaks Google Translate functionality.

Excellent add-on: it allows me to enable only what is needed to get a site working, without permitting cookies and add-ins from the dozens of 3d-party sites whose content is often incorporated into modern websites. Yesterday (2021-JUL-25) it broke Firefox's Internet access completely, but updating to v1.4.4 fixed the problem.

It works perfectly!

uMatrix unexpectedly came back from the dead! Its dev has luckily changed his mind, hurray!

Thanks for the fix for the security vulnerability!

Must be updated... :)

Excelente.
É uma pena que foi abandonado.