If you are surfing but the ads are just displaying blank pages, check the URL of the surf window. It should start with http, and not https. If you start surfing with https, it will only display https content, and most things people advertise is not https. You can log in with https, but the actual surf frame should redirect to http.
If ads aren't showing at all or if surf shows blank pages even after you have cleaned your browser's cache, it is most likely a browser addon or plugin (most likely any type of ad blocker) which is causing this. Try to deactivate the plugin, clear your cache and restart the browser. You can also often add an exception in the ad blocker for the sites you are surfing, so ads display correctly on those sites. There are guides for each plugin/addon on the page where you add them to your browsers, and you can also just google the plugin/addon name for information on how they work.
If these things happen in just one of the sites you are surfing, it doesn't mean cache is not the problem. It does not have to affect any other site you surf in so always try these steps first. If you're still seeing blank pages or can't access a site, check your anti virus settings to see if there is anything there that prevents you from visiting a site.
If there is any issue with the site itself, it would happen to all members. If only one person can't surf, this is an issue with their browser or software, and usually it's browser cache or an ad blocking plugin or addon which causes problems. You can test this by trying in another browser.
It only takes one bad ad to fill up your browser's cache, and it doesn't have to affect other sites when this happens. It can cause blank pages and incorrect clicks. It doesn't matter if it used to work earlier in the day or the day before; if cache fills up, things will display incorrectly or not load at all.