When running an SSRS report, the following SSRS error may be encountered: An error occurred during local report processing. Error in the application. Could not find the file”. Followed by the path to the SSRS file. In fact, the missing file is a file with an RSD extension and not an RDS (Report Data Source) file.
RDL reports use Report Data Source (RDS) files. Report Definition Language Client-Side (RDLC) files, on the other hand, use Report Shared Dataset (RSD) connections. That is, SSRS reports with a shared connection.
Reporting Services error: An error occurred during local report processing
The complete error in detail: “An error occurred during local report processing. Error in the application. Could not find the file .rsd”.
Indeed, encountering this error is blocking during the development of SSRS reports. And potentially time consuming if the report must be started from scratch. Especially if the report file is corrupted and unusable.
This is a report with an RDLC extension which uses an .RSD connection. Not RDL, which is the standard Reporting Services report format, which uses .RDS connections.
Solution to correct this SSRS error
The solution is to relocate the files or create the files for the previously deleted database connections. I.e., to reuse the exact same name for the connections as previously used.
Finally, to avoid this kind of error, it is very important to regularly compile the code of your SSRS project and to save your objects.
Indeed, Visual Studio is the main tool for the development of Microsoft BI projects and especially for SQL Server code.
Visual Studio 2019 via the SQL Server Data Tools or SSDT allows the development of SSIS, SSRS and SSAS projects.
To go further, the expert-only.com site is dedicated mainly to tutorials on Microsoft IT tools and SQL Server, to learn how to use SSIS, these practical English Microsoft tutorials are a good start.
Here is another short tutorial for using dynamic queries in an SSRS dataset.