How to use PrimeFaces p:fileUpload? Listener method is never invoked or UploadedFile is null / throws an error / not usable

Question

I\'m trying to upload a file using PrimeFaces, but the fileUploadListener method isn\'t being invoked after the upload finishes.

Here is the view:

Answer 1

I had same issue with primefaces 5.3 and I went through all the points described by BalusC with no result. I followed his advice of debugging FileUploadRenderer#decode() and I discovered that my web.xml was unproperly set

  primefaces.UPLOADER
  auto|native|commons

The param-value must be 1 of these 3 values but not all of them!! The whole context-param section can be removed and the default will be auto