WP Help Support on "how to get footer to display images horizontally"

Sorry, there is typo in my code "sponsors", it should be "sponsers" like yours, try

.widget .sponsers ul li {
    display: inline-block;
}

or try

.sponsers ul li {
    display: inline-block;
}

or even

.sponsers ul li {
    display: inline-block !important;
}