No usage data For Usage Metrics Report

Hi there

I created a usage metrics report using the admin account and encountered the error 'No usage data' as below:

 I deleted the dataset of the report and recreated it but had the same error, I checked the datasets setting and got the errors as following:

1. There was an error when processing the data in the dataset,The credentials provided for the UsageMetricsDataConnector source are invalid.

2. Failed to test the connection to your data source. Please retry your credentials.

I tried to edit credentials,signing in with admin account and got the error 

Failed to update data source credentials: The credentials provided for the UsageMetricsDataConnector source are invalid. 

Could anyone advise how to solve this problem? Thanks