getAppLicenseInformation via REST not working anymore against SharePoint Online

Hi,

i access the SP.Utilities.Utility.getAppLicenseInformation service via REST to determine the current Licenseinformation of my provider hosted app from the server side.

Everything was running fine, but since 2-3 weeks I get a security error back.

I correctly put the Bearer accessToken to the Authorization header and call the URL

spHost+ spSite+ "_api/SP.Utilities.Utility.GetAppLicenseInformation('"+ appData.productId+ "')"

so it is

https://mysharepointhost.sharepoint.com/_api/SP.Utilities.Utility.GetAppLicenseInformation('{myproduct-GUID}')

When I do this i get become the errror code

"-1, Microsoft.SharePoint.AppManagement.AppManagementServiceException"

with the message

<?xml version="1.0" encoding="utf-8"?>
<m:error xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
<m:code>-2147024891, System.UnauthorizedAccessException</m:code>
<m:message xml:lang="en-US">Access denied. You do not have permission to perform this 
action or access this resource.</m:message>
</m:error>

So it means, the App isn't authorized to access the license informations of the product Id.

I think my access token is ok, because I can access all other SharePoint REST APIs.

What is wrong or what has been changed?