Apple TestFlight upload warning ITMS-90191: missing `beta-reports-active` entitlement

First, be sure that you are using an App Store Distribution Provisioning Profile. This is likely a different provisioning profile from the Ad Hoc Distribution Provisioning Profile you were using to sign pre-Apple TestFlight builds.

I continued to hit Error ITMS-90191 after I switched to an App Store Distribution Provisioning Profile. I fixed the issue by additionally adding the beta-reports-active key to my Target's Entitlements.plist file in the Xcode project.

The beta-reports-active key must be included in the Provisioning Profile AND the Target's entitlements.

TargetName.entitlements:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>

    // ...

    <key>beta-reports-active</key>
    <true/>

    // ...

</dict>
</plist>

After adding the entitlement to my Target, I'm able to successfully upload the build to iTunes Connect TestFlight without the ITMS-90191 warning:

Manually editing the plist file didn't do it for me.
Editing an existing profile and generating the file also did NOT work this time.
But, just like for joehl, creating a brand NEW provision profile actually fixed it for me. So, create an all new Provision Profile and and you will be back in business. This looks like a glitch in TestFlight.

I was able to fix this by adding this to my xcodebuild script.

xcodebuild ... PROVISIONING_PROFILE=<Provisioning Profile Id>

Looks like setting Code Sign Identities in Build Settings manually could fix this problem too.