Thank you for answering; I can open Mathematica create a new notebook and be able to work in it, i have created 3 nb so far the first one was the first one that I couldn't open then I created a new one where I only input one command i can open that however the third one that I created has the same issues as the first one.

Im using Windows 8.1, however I tried to open the file in a friend's computer who has Windows 7 and the same problem occurred.

When I try to open the file directly from my documents carpet or from Mathematica this screen appears

When I press enable dynamics only the warning disappears and the nothing happens no matter how much time I left the computer without working, when I close the window it reopens whitout the bar.

Didnt work

A little update I don´t know why but after i created around 10 corrupted notebooks the eleventh and beyond work perfectly. maybe it´s a corrupted file or something

Another thing: We tried to open that file on a different machine and it didn't work either, just as described before. (Windows 7 and Ubuntu in this case) So it should be an issue with the files?

Checking the "Parse and load entire notebook into memory upon reopening" box worked for me. Thanks!

No, it doesn't work for me either. But in your notebook uncorrupter, I saw a link and followed it to this page: http://support.wolfram.com/kb/12423

I also tried what is suggested there. From what I understand, if I follow the instructions there, mathematica should open a new notebook which contains everything that could be "saved" from the specified notebook. What seems odd to me is that, at least in my case, the new notebook is completely empty. Its almost as if the procedure regards every single line in my old notebook as corrupted. I dont know much about mathematica and what one can do wrong, but as I said, I just did some numerical calculations in this notebook. I can't imagine what has happened here.

Anyway, I'm just trying to give as much information as possible, so that maybe somebody can come up with a solution. (Thanks for answering in the first place.)

It doesn't seem to work, for me at least. In the beginning I also had this problem. And it was very frustrating to see that happening. I have disabled the closing window... and the problem persisted, but in another form:

Let's say you have a new notebook containing some code. Without saving the work, close the notebook by pressing "X"; it asks if you want to save your work; indicate the location and save. Now, if you want to open this recent notebook, first try and find it!

I think I may know what is happening in this case. If you open the problem notebook in a text editor, it doesn't contain any of the information in the original file. Instead, it seems to contain the instructions to display the welcome/exit page. I think that somehow, the contents of the welcome/exit page are being saved over the notebook contents. That is why when you open the notebook it appears that the welcome/exit page just stays put. Its actually opening the notebook correctly, but the notebook has been replaced with the welcome/exit page. Tough luck.

I would recommend saving through the file menu in the future, and never just clicking the close button (X) to save.