Widget doesn't appear on my Blog


Hello everyone!
I know that this is a current topic around here but all the answers that I saw didn’t help me…
I have my blog: http://miguel-magalhaes.blogspot.de/ for the last year and everything was working just fine. However last months, has you can see, my tweets don’t appear on the right side. I tried several solutions:
1 . Defined widgets in the blogger definitions, doesn’t work (Has you can see in the website)
2 . Create my own widget in the blogger definitios ask for a code in URL.
3 . Create a widget trough twitter, gives-me a HTML code and I have no idea where should I put it in the HTML language site of my blog.

All solutions look like a dead end! Can anyone help me out?
Thank you in Advance,
Miguel M.