Helpdesk-Installation Error 401


we are trying to install a new Helpdesk-Instance with the plumsail-installer in our M365-Tenant.
I´m installing with an global-administrator.
When i´m starting the Installation i always get an Error by registering the Helpdesk-Instance.

Do you have any ideas to fix the Problem?

Hello! I checked logs and it seems that you managed with the error. Could you confirm and share what was wrong?

yeah we could install a new instance.
can you please tell me why the error occurred?

These changes in SharePoint app authentication might lead to the error you encountered. We released a fix for it and for many clients it solved the issue. We are not sure why it occurred in your case. Please let us know if it appears again and we will research it.