Either this is a test by computer learning hardware or a non-english speaking poster. I'll bite.
By apply, do you mean updated or upgraded, what exactly do you mean? Docx should work in office 2007 since that was the first version year it came out. What version did you have before when it was working? Have you tried right clicking and doing an "open with..." and choosing Word 2007? Also can you share what operating system your using? Windows 7, 8, 8.1 or 10? Which update of that OS are you on as well. A little more info would be useful in figuring out your issue.
For errors that aren't showing up, go to your start menu and type in "Event Viewer". On the left hand side select "Application" to filter out and only show events from applications like Word. See if there are any errors that are time stamped when you attempted to open up your .docx file.
Report back what errors you get.
"I think there is a world market for maybe five computers."
Thomas Watson, chairman of IBM, 1943
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