If you notice any problems with the appearance of your website try the Cache Preset Test JS first. If now everything appears normal try Test CSS and look for reappearing errors. Those are usually a product of faulty CSS code. You should check custom CSS code for a missing } - looking in media queries is often a good place to start.
@media only screen and (max-width: 1128px) {
.myCSSClass {
border: 1px solid #000;
margin: 10px 0;
}
/* closing } for media query is missing */
If the problem persists please submit a support ticket.