Before you try to install it, you can always check for its existence

If dir(Application.UserLibraryPath & DCMaster2) = "" then
'Not in correct location

Also,

With AddIns.Add(FileName:=Application.UserLibraryPath & DCMaster2)
.Installed = False
End With
With AddIns.Add(FileName:=Application.UserLibraryPath & DCMaster2)
.Installed = True
End With

Seems flawed. Why install it twice.

Perhaps
With AddIns.Add(FileName:=Application.UserLibraryPath & DCMaster2)
.Installed = False
.Installed = True
End with

although I don't think the installed = False is necessary if it wasn't in
the menu to begin with.

Nonetheless, I doubt that would account for your anomally. Checking if the
file exists with Dir would seem the most straightforward.

--
Regards,
Tom Ogilvy



"Trefor" wrote:

Tom,

Thanks for the reply.

Public Const DCMaster = "'Customer Data Collect Master.xla'"

Dim DCMaster2 As String
DCMaster2 = Replace(DCMaster, "'", "")

--
Trefor


"Tom Ogilvy" wrote:

is DCMaster of the form Myaddin.xla or just MyAddin

If the latter, then always use the extension.

--
Regards,
Tom Ogilvy


"Trefor" wrote:

I use the below code to check for an AddIn, the problem I have is the line
marked * sometimes causes an if the file is missing, but sometime the error
code is ZERO, even though the file is not installed.

I have not quite worked out what is going on, but this line seems to be
inconsistant in its result.


Dim WBName As String
On Error Resume Next ' turn off error checking
* WBName = Workbooks(DCMaster2).Name
LastError = Err
On Error GoTo 0 ' restore error checking
If LastError < 0 Then
' the add-in workbook isn't currently open. Manually open it.
On Error Resume Next
Application.DisplayAlerts = False
With AddIns.Add(FileName:=Application.UserLibraryPath & DCMaster2)
.Installed = False
End With
With AddIns.Add(FileName:=Application.UserLibraryPath & DCMaster2)
.Installed = True
End With
Application.DisplayAlerts = True
LastError = Err
On Error GoTo 0 ' restore error checking
If LastError < 0 Then
' The workbook was not found in the correct location
AddinPresent = False
Else
' The workbook was found and installed
AddinPresent = True
End If
Else
' No error so the workbook is already loaded
AddinPresent = True
End If
End Function



--
Trefor