I used to be able to call a version 7.3.3 EntireX workbench generated dll from VB6 (DCOM). After generating the dll using EntireX version 8, I am unable to call the generated dll from VB6. The error I get is:

This error is being caused by a parameter being defined as a string in VB6 and an N3 in the IDL from which the EntireX dll was generated. I am passing an empty string to the EntireX dll. When I pass a “0” instead of an empty string, there is no error. Note again, that this was not the case in version 7. The problem is that I have a few hundred dll’s where this might be a problem so changing my VB6 code is impractical. Is there a switch or setting available that will mimic the version 7 behaviour in version 8?

Did you rule out the Microsoft runtime being the source of the problem? see this for example:
[url]c# - Convert String to Decimal Mystery - Stack Overflow
Can you attach the VB source snippet and IDL?
Shmuel Coller

I dont think that the link provided is relevant to my issue because I am using VB 6 and this is not an issue with EntireX v7. The IDL is :

library 'Global':'Bracweb' is

program 'BPE001N1':'StdCodesEnq' is define data parameter
1 IP-USER-ID       	(A6)
1 IP-RESOURCE-ID   	(A6)
1 IP-FORM-NAME     	(A8)
1 IP-ACTION        	(A1)
1 IOP-SCROLL-DIR   	(A1)
1 IOP-BOF          	(A1)
1 IOP-EOF          	(A1)
1 IOP-OCCURS       	(N3)
1 IOP-CODE-TYPE	  	(A8)
1 IOP-DISP-ORDER	(N3)
1 IOP-DESC		  	(A32)
1 IOP-CODE		  	(A8)
1 OP-CODE-TYPE 	  	(A8/50) 	In Out
1 OP-RESOURCE-ID	(A6/50)
1 OP-DISP-ORDER		(N3/50)
1 OP-DESC			(A32/50)
1 OP-CODE			(A8/50)
1 OP-DEFAULT		(A1/50)
1 OP-ORIGINAL-CODE  (A8/50)
1 OP-FIELD1         (A50/50)
1 OP-FIELD2         (A50/50)
1 OP-FIELD3         (A50/50)
1 OP-FIELD4         (A50/50)
1 OP-FIELD5         (A50/50)
1 ERR-TYPE 			(A1/5) 	
1 ERR-MESSAGE 		(A150/5) 	
1 ERR-TAB 			(N2/5) 	
1 ERR-PROGRAM 		(A8/5) 
1 ERR-FIELD 		(A20/5) 	
end-define

and the VB 6 code is:

Public Sub getCodes(Optional ipUserID As String = "", Optional ipResourceID As String = "", _
Optional ipFormName As String = "BPE001N1", Optional ipAction As String = "", _
Optional iopScrollDir As String = "", Optional iopBof As String = "", _
Optional iopEOF As String = "", Optional iopOccurs As String = "", _
Optional iopCodeType As String = "")

Dim xmlNode                   As MSXML2.IXMLDOMElement
Dim xmlAttrib                 As MSXML2.IXMLDOMAttribute

Dim codetypeIN                As String * 8
Dim iopDispOrder              As String
Dim iopDesc                   As String * 32
Dim IOPCODE                   As String * 8
Dim OPEOF                     As String
Dim opCodeType()              As String
Dim OPRESOURCEID()            As String
Dim opDispOrder()             As String
Dim OPDESC()                  As String
Dim OPCODE()                  As String
Dim opDefault()               As String
Dim OPORIGINALCODE()          As String
Dim opField1()                As String
Dim opField2()                As String
Dim opField3()                As String
Dim opField4()                As String
Dim opField5()                As String
'Errors
Dim opErrorType()             As String
Dim opErrorMessage()          As String
Dim opErrorProgram()          As String
Dim opErrorField()            As String
Dim outDoc                    As MSXML2.DOMDocument40
Dim menuObj                   As MSXML2.DOMDocument40
Dim outXml                    As String
'On Error GoTo errorHandle:
Dim xmlGlobalNode             As MSXML2.IXMLDOMElement
Dim xmlDatNode                As MSXML2.IXMLDOMElement
Dim n                         As Long
Dim oldType                   As String

Set xmlNode = mvarXmlDom.selectSingleNode("//GLOBALS")
codetypeIN = iopCodeType

ReDim opCodeType(49) As String
ReDim OPRESOURCEID(49) As String
ReDim opDispOrder(49) As String
ReDim OPDESC(49) As String
ReDim OPCODE(49) As String
ReDim opDefault(49) As String
ReDim OPORIGINALCODE(49) As String
'Errors.
ReDim opErrorType(4) As String
ReDim opErrorMessage(4) As String
ReDim opErrorTab(4) As String
ReDim opErrorProgram(4) As String
ReDim opErrorField(4) As String
ipUserID = ""
ipResourceID = ""
ipAction = ""

mvarExObj.ServerAddress = commonXml.ConnectString("ENTXBRAC")


mvarExObj.StdCodesEnq ipUserID, ipResourceID, ipFormName, ipAction, _
iopScrollDir, iopBof, iopEOF, iopOccurs, _
codetypeIN, iopDispOrder, iopDesc, IOPCODE, _
opCodeType, OPRESOURCEID, opDispOrder, _
OPDESC, OPCODE, opDefault, OPORIGINALCODE, _
opField1, opField2, opField3, opField4, opField5, _
opErrorType, opErrorMessage, opErrorTab, _
opErrorProgram, opErrorField

End Sub

The line that causes the error is ‘mvarExObj.StdCodesEnq …’. This is the call to the EntireX generated dll. When the iopOccurs and iopDispOrder variables are changed from “” to “0”, the problem is resolved. Note that both these variables are defined as strings in VB 6 and that the IDL defines them as N3. Again, this works in EntireX version 7. So the problem seems to be that EntireX v8 does not tolerate blank strings for numeric variables.