Let's perform some troubleshooting steps so you can complete your pay run, ddbuilding.
Let's start with logging in to incognito window. A private browser or incognito window does not store any activities, which is why it's a good idea to use it for any unexpected behavior in the program. Here are the keyboard shortcuts depending on the browser you're using:
Google Chrome: press Ctrl + Shift + N
Mozilla Firefox: press Ctrl + Shift + P
Safari: press Command + Shift + N
Once logged in, go back and try to complete your pay run again. If this works, it means that you need to clear your browser's cache so the system can start fresh. If you get the same result while using a private browser, I recommend switching to a different browser.
Feel free to drop a comment below if you need further assistance. I'll be around to help you.