The report server cannot process the report or shared dataset. The shared data source 'XXX' for the report server or SharePoint site is not valid

Question

My error is below:

The report server cannot process the report or shared dataset. 
The shared data source 'XXX' for the report server or SharePoint site is not valid. 
Browse to the server or site and select a shared data source. (rsInvalidDataSourceReference) 

Right. I've checked all 3 data sources and they connect fine. I've deleted the report and data sources and deployed them again but still the error. I've used Notepad++ to check for the reference XXX in any of the files and still nothing.

These options are both checked.

Always run this report with the most recent data 
Do not cache temporary copies of this report 

Under Snapshot Options > Allow report history to be created manually I get a warning of Credentials used to run this report are not stored. Could this be a reason?

My data sources are setup like:

I have read other similar posts but no luck.

Thanks

Answer 1

Go to your Datasets and check the Data Source being used if it's pointing to the correct data source

Answer 2

A restart of report server resolved this particular issue for some annoyingly odd reason