Steps to resolve the issue of optional fields in SCCM ConfigMgr SSRS default report.
• Right-click the report in the console and select “Properties”,
• Click the “Edit SQL Statement” button;
• Click the “Prompts” button;
• Right-click the “ChannelCode” prompt and select “Properties”;
• Clear the “Provide a SQL statement” option;
• Click the “OK” button in all open dialogs to confirm the changes.
This will allow you to run the report without specifying a value for the Channel Code. If you’d rather not modify the original report, you can first create a copy by right-clicking the report and selecting “Clone”, and then modify the copied report instead. Either way you’ll need to copy the modified report to your SQL Reporting Services Point by right-clicking the associated object and selecting “Copy Reports to Reporting Services”.