Symptoms
Assume that you run an application that calls a method on a COM-based component on a computer that is running Windows 8. The method uses a user-defined type (UDT) that consists of a structure that is wrapped in a variant. In this situation, the call operation fails, and error code 0x800706f7 is generated.
Cause
This issue occurs because valid user-defined types are not handled correctly in one of the input buffer validation operations that Oleaut32.dll performs.
Resolution
To resolve this issue, install update rollup 2862768. For more information about how to obtain this update rollup package, click the following article number to view the article in the Microsoft Knowledge Base:
2862768 Windows RT, Windows 8, and Windows Server 2012 update rollup: August 2013