Hi @JD_ReGen
I ran a test on Microsoft Forms to get to your error (Object reference not set to an instance of an object).
In 'Press button on web page' action, captured a button in a form which gave me '<div> 'button-content'' as the object to click, similar to yours.
The button you're trying to click has a unique title/caption? If so, then in the Selector Builder of the element select only the option that contains Title = (title of your button), and uncheck all others, as in the example below:

Doing this I was able to click button sucessfully. Check if this solution applies to your case.😉