I'm not able to post links anymore

hey,
i have a problem with posting links mainly because I don't see the link button anymore. I thought it could be because I canged my settings to use facebook in https but even if I use it in http, all I see is in the picture below (its in german but you can see that there is no link button, only for posting your status, photos, video or question).
any ideas what happend or how I can get it back? thank you so much in advance.
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HTTPS shouldn't matter. You kind of don't need a link button, though. If you paste the link (Ctrl + V), wait a few seconds, and then press Ctrl + Z, it will still be attached to your post, just like if you used the link button.