Report Server stored credentials - Couldn't connect

[Anonymous]

Hi all,

I have a report that connects to a Microsoft SQL 2014 database using database credentials. It works fine when running in Power BI Desktop, but when I deploy the report to the server and try to store the data source credentials to schedule a refresh I get the following error:

"Couldn't connect. The report server couldn't connect to the data source using the information you entered..." 

Further details are:

"Microsoft SQL: A connection was successfully established with the server, but then an error occurred during the login process. (provider: SSL Provider, error:0 - The message received was unexpected or badly formatted)"

We are running the August 2018 version of Report Server, and the data refresh works fine in the August 2018 RS version of Power BI Desktop. I have tried turning off the "Encrypt connections" option in the report but get the same result.

Any ideas?

Michelle