When you use a browser it saves some information from websites in its cache and cookies. Clearing them can fix certain problems like pages not loading or formatting issues on sites.

When clearing your cache, look for a option (if available each browser is different) with the phrasing of “All time” instead of “The last hour“, this is typically needed to resolve all cache/cookie browser issues.  Also all checkboxes should be filled in for the type of data, except for stored passwords if you wish to keep them to make logging in easier.
How to clear your cache from the most common Browsers: