Sorry to hear that! There are a few reasons why this might happen, both at our end or yours.
Please make sure you are on a solid broadband connection and if possible plug your computer into your router via ethernet rather than wifi. It is possible a wifi dropout can interrupt an upload and cause it to fail.
We have a file size limit of 12GB. If you're trying to review or approve a file larger than this, we recommend either uploading a lower resolution format, or splitting the project into multiple parts. Remember, our video player can output full HD, so 4K files will be reduced to 1080 in the viewing window anyway.
It is also possible that an error in your browser cache is corrupting your files on upload, preventing them from encoding in Wipster. The best way to solve this is to simply clear your browser cache, which conveniently fixes most issues users run into with Wipster.
If you've checked all of the above and still aren't able to upload an asset to Wipster, please let us know by emailing us at email@example.com.