D1133: Buffer Precision Unknown Not Allowed
D2D1_BUFFER_PRECISION_UNKNOWN is not allowed as a parameter to this API.
Direct2D allows an application to specify a desired buffer precision for some operations. For example, the precision used for the imaging pipeline is specified using ID2D1DeviceContext::SetRenderingControls. The BUFFER_PRECISION_UNKNOWN specifier allows an application to forego this setting and Direct2D will use a default value, but this specifier is not allowed for some operations. In particular, it may not be allowed during creation of a gradient stop collection.
Ensure that the BUFFER_PRECISION_UNKNOWN specifier is not used with ID2D1DeviceContext::CreateGradientStopCollection. Use a known precision value; consider using the precision of the target surface format for the operation.