BeforeCreateNewObjectFinalize and External Objects

We have an event handler script that explicitly excludes an externally maintained Project object:

' Get the user name
Dim userAccount
Set userAccount = Vault.UserOperations.GetUserAccount(CurrentUserID)
Dim vloginName
vloginName = userAccount.LoginName

'Get instance of Property values
Dim oPropVals: Set oPropVals = CreateObject("MFilesApi.PropertyValues")
Set oPropVals = Vault.ObjectPropertyOperations.GetProperties(ObjVer)

currentTitle = oPropVals.SearchForProperty(MFBuiltInPropertyDefNameOrTitle).TypedValue.Value

currentClass = oPropVals.SearchForProperty(MFBuiltInPropertyDefClass).TypedValue.DisplayValue

If ( currentClass <> "Project") Then
If ( ( (InStr(1, currentTitle, "!") > 0) _
or (InStr(1, currentTitle, "~") > 0) _
or (InStr(1, currentTitle, "@") > 0) _
or (InStr(1, currentTitle, "#") > 0) _
or (InStr(1, currentTitle, "%") > 0) _
or (InStr(1, currentTitle, "^") > 0) _
or (InStr(1, currentTitle, "&") > 0) _
or (InStr(1, currentTitle, "*") > 0) _
or (InStr(1, currentTitle, "?") > 0) ) _
and (InStr(1, vloginName, "mf_service") = 0) ) _
Then
Err.Raise MFScriptCancel, "Please remove the special characters in " + currentTitle
End If
End If

Yet, full refreshes of the Project object fail to complete.  Watching the refreshing status, I can see that objects are not updated or inserted.