I am running 2.9.3 using Channel Forms, the issue is if I try and upload a excel or .xlsx file it never uploads, even though eventually the form submits (it's considerable slower submit), no upload happens.
If I try .txt or an image file, it's fine. I have the enctype="multipart/form-data" in the tag, so not sure what might be occurring here. Any ideas, I have been at it for a while and not sure what it might be.