Annoying "The report server cannot process the report or shared dataset."

I was recently stuck with an annoying error in the solution that uses SSRS. We have a SharePoint application with SSRS report infrastructure - reports library, shared data sets library, shared data connections library. After several deployments and migrations of report files between environments I started getting an error "The report server cannot process the report or shared dataset. The shared data source '4ba55136-5726-4cc3-b5e8-51768f451583' for the report server or SharePoint site is not valid. Browse to the server or site and select a shared data source." It was an attempt to open a report file. GUIDs in your case will of course be different.

I downloaded report and shared data set files and was trying to find anything wrong in them. Nothing was helpful. No GUIDs like in the error text. The solution came when I started analyzing Reporting Service Application content database. When I opened the DataSource table I found the above mentioned data source GUID in the DSID field and what was suspicious - the Link field had no value for this Data Source. 

We use a single Data Connection in that scenario and its GUID was mentioned in the "Link" field in some other records (the one started from 14b91e87-...).  I copied this GUID value to the "Link" field of the record for the shared data source affected by the error and reopened the report web page. I've got no errors!

So that was a problem of Reporting Service content database and I have no idea why the information broke but it definitely can happen. Of course the easiest and more correct approach would be to redeploy the entire report project to SharePoint but it may not always be possible.

by Maxim Khoruzhiy via Everyone's Blog Posts - SharePoint Community