Accordingly your file should be placed in the 'uploads' folder. But it is'nt happening.
Try to check following solutions.
Clear the app data and cache from app info in settings, and log in to the account and try again.
If it isn't working, What is the size of the file that you are uploading? If its to large, try to upload in modules. According to my experience large files are uploaded but it takes time and meanwhile it doesn't even show you the progress for very large files. So if its in gb or some 500 - 700 mb try to upload in modules.
If still it doesn't work try to upload a simple image file using the same procedure that you used before just to counter-check. If this small image is uploaded then the problem persists in the app in the form of a bug which do not uploads a large file.