Missing parameter values

Hello,

I'm using Crystal Reports 2008 and ASP.NET 3.5.

Suddenly one of my reports started to give me an error message: "Missing parameter values."

I did the research and found many similar issues, but they all apply to the reports with parameters. But I'm not setting any parameters to this report, I'm only passing parameters to the stored procedures, so I have no idea where this message is coming from. The same report worked fine yesterday, and I even don't know what has been changed.

The only special thing about this report is that it has two subreports. But all my other reports with subreports work just fine.

I would appreciate any suggestions about this.

Thank you,

Peter