Error when open Report

1. Problem:

   Error when open a Report: 

   The report server cannot process the report or shared dataset. The shared data source 'a5388c96-fe18-464e-8cd6-60833fa7447c' for the report server or SharePoint site is not valid. Browse to the server or site and select a shared data source. ---> Microsoft.ReportingServices.Diagnostics.Utilities.InvalidDataSourceReferenceException: The report server cannot process the report or shared dataset. The shared data source 'a5388c96-fe18-464e-8cd6-60833fa7447c' for the report server or SharePoint site is not valid. Browse to the server or site and select a shared data source.

   See also screen attached.

   Solution:

   Open Reports Library, choose All Documents view, click Manage Data Sources for the dataset of the report with error:
   

   on the next screen click Title of the DataSource: 
   On the next screen verify that Data Source is not empty, if it is empty choose Data Source:
   
   and Save all Changes.

   Verify that report is working now.