In addition, if you click on the option to "Bring forward (prior year) data to (current year) for all plans", the following warning will appear in a pop-up window:
When you are ready, click on "OK" to proceed. It may take a few minutes to process. Once the process is complete, you will be brought to the "Bring forward Form 5500 data to (current year)" screen with results shown indicating the number of forms updated.