Getting "Cannot verify client. (3000)" when trying to upload archive from Xcode to itunesConnect

Just updated to Xcode 7.1 and getting this error. Was able to upload fine using 7.0.1

Hmmm, well a restart of Xcode, a fresh clean, build and archive seems to have fixed it.

If you encounter this error, you have two options:

Option A - Engage in an activity that takes a minute or two. Could be any of the activities described in the other answers, like re-install XCode, renew certificates, do a new build from scratch after clearing caches. Or simply go get a coffee.

or

Option B - Do nothing at all for a little while.

Then, try again. If it doesn't work, repeat.

Just updated to Xcode 7.1 and getting this error. Was able to upload fine using 7.0.1

same here - restart, clean build, archive and upload was successful.

Same problem here. Grabbing a cup of ☕️ worked for me.

Exporting the app as an .ipa and uploading via Application Loader 3.0 worked for me. (Restarting xcode, cleaning, and re-archiving did not.)