I can't tweet. If I type a tweet out the writing comes up paler than it used to and there is no button to post the tweet. If I try clicking on the blue button to compose a tweet nothing happens, as if I hadn't pressed it. Many buttons do nothing when I press them, I couldn't even edit my account settings until I found the link to this page and pasted it into my search bar. I am using quite an old mac but have only had problems in the last couple of months. Please help.