The problem is, that the same Firefox browser doesn't let me mine now. This is what I get:
Error: This browser does not support WebGL.
Loading math libraries...
On Chrome, the mining works without any issue. Any reason, why this error occurs on Firefox?
Hmmm, not sure why you are getting that error. Mining seems to be working on our Firefox instance. What version is your Firefox?
It's the latest one (Windows). I found the issue. If I type in address bar about:support, under Graphics, I noticed this:
WebGL 2 Driver Renderer WebGL creation failed: * Refused to create WebGL2 context because of blacklist entry: FEATURE_FAILURE_BUG_1457758
Not sure why it is like that only on Firefox. As I said, on Chrome, it works fine. I found workarounds on the web on how to force the Firefox to use it, but I rather not do that. I guess I'll simpy use Chrome instead.