Please select more than one platform. If you want to make changes to only one platform, cancel out of the Multiple Platforms dialog and select that platform from the platform drop-down.
This error generally occurs when a single platform has been selected in the Multiple Platforms dialog box.
To correct this error
Select additional platforms.
—or—
If you want to update a single platform, choose Cancel and select the correct platform from the Platform list.
See Also
Reference
Configuration, Configuration Properties, Solution Property Pages Dialog Box