Dynamics 365 BC V15 Problem with Extensions (Scope:Tenant)

manlue

Hi, I'm working on an customer Upgrade and finished it to Dynamics 365 BC V15. It's running and all Data was migrated fine. Customer ist testing. We are still working on individual customization App which I now wanted to upgrade. But installing the new individual App throws an error: one page extension Id of our new individual App-Version is yet used by another app. This is an App created by a test-user who customized a page. Now we know not to use page-Extension-ID's in range 50000... But: I'm not able to delete the app that was created by the test-user. It's shown in PowerShell "Get-NAVAppInfo..." but not in Webclient "Extension Management". Trying to uninstall it in PowerShell throws error "App ist not published". Trying to unpublish it in PowerShell throws error "App is in use". Trying to Sync-NAVApp in PowerShell with "-Mode ForceSync" throws error like "cannot do until app is uninstalled". SQL-Database Tables "dbo.NAV App..." show these Apps in "..published Apps" AND "..installed Apps". There are some Apps with this beaviour, all of them are of Scope:Tenant.
I know that a few days ago the acount of the Service was changed from "Net Account" to a User Account. This was done by the technicians because another company customizing their App thought to nee this. Meanwhile this change is undone. It may be possible that all of this crazy Apps were created since this change in Service Account. Somebody has an idea? It's not a hint of our work now (we changed the pageextension id) but it's a crazy thing, isn't it?