Reset instance is failing
First, try to use the functionality at least one more time within a few hours of your first try to ensure it's not a temporary issue.
If it still fails the reason might be a dependency on our orchestration engine that seldom fails.
While issue is under investigation, in the meantime microsoft support can unblock you by using ACIS commands.
Recommended steps:
1. Ask your tenant admin to open a support ticket here: admin.powerplatform.microsoft.com/support.
2. Before sending the support ticket, optimally add the following request to microsoft support: "I received the recommendation that support will use the following trouble shooting guide (accessible via global search): Reset instance is failing".
Thank you,
The Microsoft Dynamics 365 Customer Insights team