The invalidVariant managed debugging assistant (MDA) is activated when an invalid VARIANT structure is encountered during a call from native or unmanaged code to managed code.
Unexpected behavior during a transition between native and managed code involving the marshaling of a VARIANT to an object.
Native code is passing a malformed VARIANT structure to managed code. The runtime attempts to marshal this VARIANT to an object and activates the MDA if the VARIANT is not valid. Examples of invalid VARIANTS include a VARIANT with VARTYPE VT_EMPTY | VT_BYREF or a VARIANT with VARTYPE VT_VARIANT.
The native or unmanaged code passing the VARIANT must ensure that the VARIANT is correctly formed and initialized.
The MDA has no effect on the runtime's behavior.
An MDA message indicating that the runtime detected an invalid VARIANT passed to managed code by an unmanaged module.