Did you try to call the method w/o any parameter?

>Just tried but no change. I'm still getting an unknown com status code. (See attachment)
>
>>WAG, try to use an object type null variable
>>

>>if llError 
>>    loSession = CREATEOBJECT("Empty")
>>    loSession = NULL
>>    lnErrorCode = loThirdParty.getLastErrorCode(loSession)
>>endif
>>

>>
>>BTW, it's totally unnecessary to compare logical values with .T./.F.
>>
>>>I'm accessing a third party dll which has a getLastErrorCode-method.
>>>After initiliazing the object, I have to begin a new session.
>>>If I can't establish a session, i want to retreive the last error code. This method has the session-object as an incoming parameter but when i don't have this object, the parameter can be set to NULL.
>>>When I do this in Visual Studio I send 'null' to the method and it works fine, BUT in VFP any value I send works (NULL, .NULL., "", .F., 0, ...) I always get a 'Unknown COM status code'.
>>>
>>>Does anyone know what value to send ?
>>>If i have established a session and i send this session-object as the parameter an errorcode is returned.
>>>
>>>------------------------------
>>>
>>>loThirdParty = CREATEOBJECT("CISComWrapper.CIS_ComWrapperImpl")
>>>
>>>llError = .F.
>>>try
>>> loSession = loThirdParty.BeginSession()
>>>catch
>>> llError = .T.
>>>endtry
>>>
>>>if llError = .T.
>>> lnErrorCode = loThirdParty.getLastErrorCode( NULL ) &&& this is the parameter I'm talking about
>>>endif
>>>
>>>loThirdParty = NULL