Depending on the language used for the client, error conditions in Multisim result in different behavior in the client.

Visual Basic automatically interprets the errors and raise an exception. That is, any error in Multisim results in an exception in the client. Therefore, when writing a Visual Basic client, it is a good idea to use OnError (for Visual Basic 6.0) or try …catch (for VB.NET) syntax around calls to Multisim.

However, in C++, a call to Multisim that causes an error simply returns E_FAIL as the HRESULT and it is up to the client application to decide whether to throw an exception or handle it in some other way. Similarly, in LabVIEW, a failure code is returned if any errors occur in Multisim.

Please refer to the documentation for the client language for complete details on how COM works.