The MultipleItemsChanged event has been removed in QuickOPC 5.33. It is available in versions up to 5.32.

The reason for the removal was that after close investigation, there were no considerable benefits to actually having it. The original idea has been to provide better performance, but in reality that was not the case.

You can simply use the ItemChanged event. Your code becomes even simpler, because you won't have to loop through the array of changes received.

If you still decide that you need an older version, let me know here again, and I will send you the necessary link (they are not public).

Best regards