The BlueImp jQuery File Upload GitHub project has been marked "This repository has been archived by the owner. It is now read-only.".
See: https://github.com/blueimp/jQuery-File-Upload
But there has been no explanation or post from the developer. No succession or continuity plan. The developer states that Stack Overflow is the official means of support for this plugin, so I am posting here since I can't post on GitHub to ask as its read-only now. Any insight from anyone or the developer would be great as we use this plugin heavily in PrimeFaces.
My guess is that as the project is archived the author probably isn't supporting it anymore and so likely isn't going to be monitoring stack overflow to answer questions anymore. According to github they haven't contributed in a few months. It's license is open source and very permissive so if you use the code a lot you should probably consider forking it and taking over supporting it. You could also always reach out to the author through their home page https://blueimp.net/