Why do I get the Launch FFC-1 error message?

Question

Error message when trying to open Yahoo mail

Answer 1

The official answer:

Yahoo mail is currently inaccessible to some users. We are working to correct the issue and restore all functionality immediately. We know that this may have caused some inconvenience and we apologize to our users who might be affected.

There is currently a major outage. Its hitting a great many people.