In this post, you’ll learn about the error “TRUST_E_SUBJECT_FORM_UNKNOWN 0x800B0003” that is returned when working with COM based APIs or libraries in Windows.
COM Error Message
TRUST_E_SUBJECT_FORM_UNKNOWN 0x800B0003
What is COM?
Microsoft’s COM stands for Component Object Model. Component Object Model (COM) is a networked, object-oriented framework for building interoperable binary software components. Microsoft’s OLE (compound documents), ActiveX (Internet-enabled components), and other products are built on the COM base technology.
Error Description
Below is the description of this COM Error.
The form specified for the subject is not one supported or known by the specified trust provider.
