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.

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!

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.)

Try this to open the problem notebook:

File menu - Open
Locate the file and click ONCE to select it
Click the Options button low in the file navigator window
In the window that opens, check "Parse and Load Entire Notebook .."
Close the second window
Click OPEN in the file locator window.

See the screen shot.

This will rebuild some internal information that might be keeping the notebook inert.

I've got the same problem. I got mathematica 10 for work, and I have two files. One opens without any trouble, with the other one it is the same issue as described above. (The file contains possibly unsafe dynamic content) Clicking on x or on "enable dynamics" does not seem to do a thing. Both files just contain some simple calculations and no actual programming (but rather a lot of those, so recreating them would waste several hours...), therefore I can't imagine why the problem occurs. But maybe this is just because I'm new to mathematica. Anyway, help is much appreciated because I can't do a thing right now :(

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

Didnt work

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.