AJAX file upload

I have been using the partial entries add-on with the ajax file uploader with great success. The form is multi-page and so the ajax file uploader is needed to save the files as they are uploading and allowing the user to return later and complete the form. However, over the last month, it seems that the ajax file uploader is causing issues where it removes the user_id from the created_by field in the database, therefore orphaning the entry. I now see that the ajax file uploader is not available via WordPress anymore and know that was a third party plugin.
Last I knew, partial entries did not support file uploads. Does anyone have a recommendation for a file uploader that will keep the file for partial entries and/or any info that I may have missed?