This document outlines some common reasons VPP will fail to install or license applications. Before reviewing this article, confirm if the app you're experiencing issues with is being pushed through user assignment or device assignment. For an overview of VPP and these two methods of deploying apps, see this guide.
When a device fails to install an application it has been scoped for, navigate to the client details page (Systems manager > Monitor > Clients, select the client) and review its event and activity log for more information. Instructions on how to locate these logs, as well as some of the common error codes you may see here, are detailed in this article.
In the below screenshots, for example, Angry Birds 2 was not installed because a license for the app could not be found in VPP. If the root of the issue cannot be determined from the logs, consult the 'Troubleshooting Checklist' below and review your Dashboard configurations.
If VPP is unable to install or license applications, review the following configurations/requirements to identify any potential issues:
Check that a valid VPP account is linked in Organization > MDM, and that your dashboard admin account has permission to access licenses. Device assignment can also be disabled on a per network basis.
Ensure your devices meet minimum operating system requirements. User assignment requires iOS 7+ or OS X Mavericks and above, while device assignment requires iOS 9+. You can check the device's OS version in the client details.
If any of settings above was misconfigured and corrected, you can attempt to re-license and reinstall an app immediately for a set of clients from the bottom of the app page (Systems manager > MDM > Apps, select the app).
If all of the above are correctly set and you're still experiencing issues, check the VPP "Recent Activity" section for confirmation that your user or device was successfully granted a license.
You can also check the event and activity logs again at the bottom of your device's client details page for any errors regarding. See instructions and a list of error codes here, and contact support if you need further assistance.