Something went wrong with PowerBI report

Got a request from a customer earlier today about very strange error:

Something went wrong Unable to load the data model for your Power BI report. Please try again later or contact support. If you contact support, please provide these details. An unknown error has occurred when attempting to load the report data. Please contact your system administrator.: Request ID: 448f3cae-3a15-9a9a-f715-7b67812b8fd5 Status code: 500 Time: Thu Oct 10 2019 15:40:13 GMT-0400 (Eastern Daylight Time) Version: 15.0.1102.299

After a little research it has been discovered that errored report does not hit a database at all.
Which led to an idea of wrong credentials.
After credentials were updated customers were able to successfully run the report.

Here are the easy steps:

Step #1. Right click on the report's three dots (...) and choose "Manage" from the list.

Step #2. Select "Data sources" in the report's left panel.

Step #3. Update user credentials.

I haven't had time to investigate the issue, but it looks like after report was deployed and tested, something went wrong and credential record from the newly loaded report stopped matching Server's credential record, which stopped report from running.

The idea is: to use windows authentication or re-establish credentials after every new deployment.