I’ve had the CSRF problem since last March, when I first got Firefox 51. Now I have 57.0 (64-bit) on my Windows 8 laptop. I started this thread about the problem: Please Explain “CSRF Failed”
I’ve never tried going on vacation, but I can’t create or accept challenges using Firefox, nor edit my profile page. I’ve never done anything further due to lack of time and energy, but I guess the only hope is to contact the Firefox help desk. I’m not a computer guy, and I don’t even know what CSRF stands for, though the web seems to say it has something to do with authentication. Regular updates from Firefox have done nothing to fix the problem.