Both rails applications have an CSRF authentication problem in my local dev environment

Question

I have two rails applications. From one day to another both produce an ActionController::InvalidAuthenticityToken exception. I can call the login page, but when I try to login, the exception raises and in the console I find "Can't verify CSRF token authenticity".

What I tried:

• different browsers
• I checked out older releases from which I definitely know, that it had been working.

I do not post any code because I do not think that it would help. It must have an external reason, because the problem occurred on two separate apps in the same moment.

Answer 1

The reason was, that I forbid Cookies for localhost in Chrome.

What I can't figure out is, why I had the same problem in Opera, though I did not forbid cookies there.