Solved it by myself...
It is a little bit tricky and I've made a Tip&Trick and posted here in CP to allow anyone who would find him/herself into that situation to cope with it.
The word file had corrupted itself who knows why.
At the end it is not complicated to solve it. Take a look at the T&T here:
Solve Black Squares on Word Titles[
^]
Thank you all who have tried to help! :thumbsup: