@sanjaymani Does the mobile devices reporting the Serial Numbers ? This might happen if the mobile devices does not have serial number in Inventory.

Thanks.

Thank you Karthikeryan, Yes i managed to find one device which didnt have a serial number and ive removed that device from the portal. But still getting the same error. 

Check for all the devices. This issue occurs when devices don't have serial number.

Thanks.

Thanks mate. i just had a look and all the managed devices got serial numbers assigned to them. Super weird. Any where else i should look in to?

Hi
I've seen this at times for applications where not all of the settings have been set on a new app on the JAMF Pro end. In our environment we assign per device not user. So we have to make sure we check "Assign Content Purchased in Volume" and make sure the correct location is set. 

@sanjaymani Check for the below option as @AntMac suggested. 

 Thanks.

Thank you @AntMac We have set that setting to our ABM and we have enough licences too for the apps. Not sure why it still causing an issue. Do you think its a good idea to get a new service token from ABM and reconnect the volume purchasing settings ?

It's worth a shot if you've exhausted other avenues.

Do your app license totals match in both places? If it's a free app then just nudge the total by one or two in ABM to verify. 

Renewing the Volume Purchase Program (VPP) Service Token (Even though it was not expired yet ) fixed the issue for me.