I tried to upload the app build using Xcode but I got this error "no accounts with itunes connect access" I then tried to upload the IPA using application loader and I got this error "Exception occurred when creating MZContentProviderUpload for provider. (1004)"
It seems like a temporary issue with apple. Trying few times to send worked and the upload was successful.
For me just log out on Web iTunesConect / AppsoreConnect portal.
Quit Xcode (if Possible restart) and then upload the build.
If you close all the other app and upload build in sylo makes a job easy.
Also using the "Application Loader" is a Good Solution!
I was getting this error many times during 3 hours. Sometimes along with other errors with it.
What helped: re-loginning to
itunesconnect and restarting Mac after that. Build has uploaded from 1st attempt.
I got this error when I log in a different account in another app(iBook log in as my personal account). I solved this by re-login in xCode, re-archive the app, upload again.