Problems to share content on Facebook from High Sierra

Since two days ago that i can´t share nothing on Facebook from mi iMac and MacBook Air. When i wanna post a video from youtube or a song from iTunes for example, a message appears asking me to enter my password, I do it several times but it does not work. I guess it's a Facebook problem and not my Mac. At some point it happened to me and after restarting the system it was fixed, but now I had no luck.

Another thing that happens to me, also from the same moment, is that Twitter says that can't authenticate me in the notification center. But in this case i can share content from Twitter. I enclose a photos of both problems so that it is better understood.