No attachment button when composing a mail

No attachment button when composing a mail

Hello! Since some time, when I compose a mail, I don't have an attachment button, nor any formatting option in the task bar (the bar just above the text area where you write the text of the mail). There are some separators (gray vertical bars) and the spell-check button. Everything else has disappeared. I'm using Firefox, but I've tried on a different computer with a different browser (Chromium), and it's not better. I've played with the settings (trying to compose in a new window), with no more luck. But I have another Zoho account (registerer at zoho.eu and not zoho.com), and there all the formatting buttons including the attachment button (which is really the most important one) are present when I compose a mail. So I guess it's not Firefox fault. And it's just linked to one of my account (but sadly it's the one I use).

What should I do? I really need the attachment button!