Preview Button disabled

[MiddleTommy]

I have created a few reports with DateTime parameters. Everything work ok with the designer. Now I have a report with a long parameter. All other parameter settings are the same as with the DateTime parameter reports. When I preview the report in the designer it says I need to supply a parameter just like to other reports. I enter the parameter but the preview button is disabled and wont print. I tried re-creating the report and the same thing happens. I go back to the other reports and the preview enter parameter works. Why is the preview button disabled? If I supply a default value for the parameter all works ok.

[Peter]

Hello MiddleTommy,

The DateTime Report Parameter has a default value set to today's date for the Report Designer Preview and Windows Forms Report Viewer for versions prior to Telerik Reporting Q2 SP1. On the other side if you don't want the designer to demand certain Integer parameters you have to explicitly set the AllowNull to True or add a default value. Additionally the Preview button is being enabled after you move the focus out from the parameters editor.

Greetings,
Peter
the Telerik team