Mismatched User Environment

MIsmatched User Environment occurs when Apple returns a BadDeviceToken error for the affected devices (see Table 8-6 for more details).

This means some devices are tied to a different environment (Sandbox, Development, Ad Hoc, or Production) from your sending environment and cannot receive push. If you uploaded a Sandbox certificate when testing locally, and then released the app on TestFlight or the App Store (Production Environment), those original test devices are not tied to the Production Environment and cannot "switch" environments.

Steps to Resolve

Devices on the Sandbox or Ad-hoc environment will need to uninstall the app and re-install it to be on the Production Environment.
Clear the warning in Settings, select the Apple iOS Configuration, and then press Save on the next screen. The next time you send to iOS, check if this warning appears again.
Please make sure you're using our latest SDK. Our SDK is frequently updated to meet Apple's changing push standards.
If you have uploaded a Sandbox push certificate, please upload a Production Push Certificate as well.

If you're still having issues with this, please provide iZooto Support with:

Your iZooto App ID
The APNS .p12 certificate uploaded on the panel