I can confirm the new support for Edge Chromium:

Congrats!

With this new RC I deleted in C:\ProgramData\Kaspersky\SafeBrowser folder for FireFox, and now it's working fine when logging my bank, not getting Content Encoding Error, don't know it is enough or I would also delete cookies and cache of the browser?

Finally yesterday night got this new RC via auto-update, and again it went fine...

I finally could reproduce again the issue...

I deleted cache and cookies of my FF, also deleted in C:\ProgramData\Kaspersky\SafeBrowser -> folders for the 3 browsers: FF, Chrome and Edge Chom.

Using AdGuard version 7.3 (last beta), but even disabling its protection the issue is reproducible.

Tried also with Anti-Banner disabled and enabled, same results: in FF got Content Encoding Error, in Chrome blank page...

Probably it is an incompatibility with AdGuard...

Traces: https://cloud.qainfo.ru/s/lxwpuGkP5ew60zp

Ok, but being already in SM session (with green frame)?

Sure!

Just got it via auto-update, I will test with it soon!

Just got it via auto-update

It seems is working fine with FF now with build KTS 42.1482...