Cannot select trial version checkbox in Market Place

When you upload your app into Market Place, sometime you cannot select trial version checkbox because the checkbox is grayout.

The most important thing is that you need to use IsTrail() method in your app if you provide trial version.

• Try to use IsTrail() method

IsTrail() method's document is here.

LicenseInformation.IsTrial Method

Also see here.

Appendix A - Tools, Frameworks, and Processes

Creating Trial Applications Overview for Windows Phone

Sample code is here.

using Microsoft.Phone.Marketplace;

        
public static bool TrialVersion;
LicenseInformation licenseInfo = new LicenseInformation();

TrialVersion = licenseInfo.IsTrial();

if (!TrialVersion)
{
    button1.Visibility = Visibility.Collapsed;
}
else
{
    button1.Visibility = Visibility.Visible;
}

When you use IsTrail() method, the method communicate with Market Place and check your status. So, you had better use IsTrail() method only once in your app.