Odk form saved as file

I somehow saved my form in form file instead of file while trying to edit it. When I try to open the form with odk build it shows form is unable to open check it's accessibility and try again. How do solve this problem because I need to make a correction on the form?
I am using odk build 0.3.4. windows 8.1

Tried to reproduce the problem but I couldn't

Tried to see if I could change the file to odk file instead of just file as seen in the properties of the form uploaded below

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Windows usually hides your file extensions by default. If you open your Folder Options settings on your computer and go to the "View" tab, you can uncheck the box that says "Hide extensions for known file types". Then press the "Apply" button.


Now you will be able to see and edit the extensions for files in their file name. Go to the folder holding your form and add the correct extension to the filename.