I was experiencing the same issue of "Pending - Application is not available to install" with v9.81 and device based assignments.

Fixed in my environment by:
Global Management >VPP Accounts > select account > content tab > "update purchase content" button

search for VPP app that is failing and select add.

The above solution should help. Next to each app is also a refresh to do the same thing.

My problem was when the iPad went into a lock mode and the screen went dark after restarting iPad. The teacher using it said she turned on Accessibility mode and adjusted a few settings in there. So I had to wipe the device and reinstall everything. The apps were still assigned to the created apple id so I thought it wouldn't be an issue, but it never cleared the apps from the user account locking the apps in use. So I tried the refresh next to an app and "update purchase content" below, but you have to search for the app in question and just add it again. I also went into Self Service and clicked on app to see if it would install and it did, so I can't exactly tell you which sequence worked for me. Not all the apps installed automatically either. I would clear any failed apps etc that may hold up new app requests. They are slowly coming down, but I just cancel apps hanging and may just repeat the steps. Good luck.

Update:
Do what Maxim suggests

Fixed in my environment by: Global Management >VPP Accounts > select account > content tab > "update purchase content" button search for VPP app that is failing and select add

And if you continue to see issues, try this.
Find the device in question with the hanging apps and check the Management tab and click the Update Inventory button to see if that changes the status of the app to pending... If so, give it time, if you see an app still saying "Pending - Application is not available to install" go to Global Management >VPP Accounts > select account > content tab > and just Refresh the individual app.
Then go back to the device in question and see the status change to Pending. Just give it time to sort itself out and you should see your app install within a few minutes.

Just wanted to chime in to say that the above solution did not work for me. I still the the "Application is not available to install" message.

I am having this problem as well I am on iOS 9.1

I too have seen this more than enough times on iPads. I have some troubleshooting steps that I go thru that usually clears the issue:

1. Refresh the App for the VPP account (what Maxim suggested)
2. Refresh the license count in the JSS for that app. (very similar to #1 but just hit the Refresh button next to the app)
3. Login as the Apple ID (if you can) at https://appleid.apple.com/. (I think this clears a lockout of the Apple ID or something like that)
4. Login to the iTunes store as that Apple ID. Accept any new EULAs that might pop-up
5. This is a little tricky.... Make sure the user, device and app catalog entry are all set for the same site in JSS. I have found that if they are on different sites, the app will either not show in Self-Service or look like it wants to install but not.
6. Swear this one has worked from time-to-time. Just reboot the ipad.

All of these have worked for me. In combinations or not.

Hope this helps!

EDIT: I forgot a big one. Restart Tomcat on the server...yep. We have had everything look OK in the JSS but actually there was no comms between the JSS and Apple's Magic Cloud. Restarting tomcat fixed it. Done that 2x now.

I have tried everything on here to no avail. Can an admin of these forums chime please chime in?

Can confirm that lehmanp00's that process works

I have tried all suggestions above, including restarting the topcoat - nothing works for me either.

Have you tried clearing out all the pending commands so they can be reissued? There's a way to do this in bulk through MySQL if that fixes it for one iPad.

@anitasmith

The whole VPP thing is very picky on many fronts. You have to have all your 'Ducks-in-a-row' for it to work correctly.

Since iOS 9 came out, the requirements changed a bit from iOS 7/8. (of course none of this was communicated out very well)

Basic workflow is this: (for VPP Managed Distribution)

ALL apps (Mac or iOS, free or paid) should have a VPP managed license.

An MDM needs to know about that license (in this case JSS)

The License needs to be assigned to an Apple ID (at this point, the Apple ID should see the app in the purchased tab of the App Store app and can install from there)

(* Remember, the Apple ID needed to accept a VPP invite for each VPP account it might get licenses from)

The App needs to then have an entry in the MDM App Catalog (So Mobile Devices>App in JSS)

The App entry then needs to be assigned either to a user/group/ldap group or device so it shows up in Self-Service.

There are a few differences you could have:

If you want to assign VPP licenses to iOS 9 devices than you can skip assigning to Apple IDs.

Under-13 Apple IDs will ALWAYS ask for the Apple ID password when installing apps unless they are installed thru Self-Service. (that part really upset my K-12 org. Long phone calls with our Apple rep on that)

Where things bog down:
The JSS isn't getting updated info from the Apple Cloud (VPP licenses info mostly)
Apple ID never accepted VPP invite
Apple ID is locked on Apple's end
Device not at iOS 9
Device cannot communicate with the JSS correctly

This, in my experience, is the most common:
The JSS isn't getting updated info from the Apple Cloud (VPP licenses info mostly)

*one other thing to try...
Login to your VPP accounts and download a new token for the JSS. Then upload that new token to the VPP account in JSS. That can refresh all the secret Apple protocols that the JSS uses to talk to the VPP accounts.

Fix for me was to run this in sql on the JSS(should fix this in bulk):

update vpp_admin_accounts set licenses_since_modified_token = '';

Then be sure to restart tomcat.

Gabe Shackney
Princeton Public Schools

Check your VPP token expiration date.
Go to Global Management >VPP Accounts > select account > content tab > Expiration Date: Date that the service token expires.

If this is expired it will not work. You have to download a new one from the Account Summary of your VPP account.

I was able to fix this issue by adding the iPads to the exclusion list for the app in question. After forcing an 'Update Inventory' and making sure the iPads received the update command, I removed the iPads from the exclusion list. This allowed the app to install without errors.

I would like to take this opportunity to thank JAMF and their support. With their help I would STILL be trying to fix this issue.

@gshackney where exactly do we type that

It's after you login (in terminal) to sql on your jamf server and run the use jamf software command then the command listed above.

Reach out to your jamf buddie for more info on getting into sql. Be careful with sql commands if your not used to them or you could really screw things up lol.

Gabe Shackney
Princeton Public Schools