Website Displays wrong on some compters

What could be the cause of this and how could I fix it?

There are various possible causes – different browser for in – in which case start fixing the mark-up errors –

https://validator.w3.org/check?uri=http%3A%2F%2Fdieselfuelling.co.za%2F&charset=%28detect+automatically%29&doctype=Inline&group=0

The sucky part is the other site chemicalhoses.co.za worked well and now it also does what these other 2 sites are doing! Is this a recent upgrade or something?

Have you validated the other site for mark-up and CSS errors? What browsers are the problems on?

Yea they all have a bunch of markup problems. On my computer they all work pretty much 100% on all the browsers (firefox,EI and Chrome). But on other computers it looks funny on all the browsers.

Might be that they are using cached CSS files on your computer. Try clearing your browser caches.

Did and it still looks fine.Tried it on someone elses computer and it looks 100% and their a 1st time visitor. I’ll see if I can fix these markup issues. I’ll let you know if it worked.

I’m quite confused as to where to find these errors that the validator are giving me?! What pages are these errors from? To go through every wordpress page would be crazy! Any help?

You have to use the validator info to track down where those errors are coming from – what’s outputting that code – could be the theme, your content or a plugin.

BTW, not all “errors” are problematic…but some of those likely are.

On a different approach, have you tried deactivating your plugins and switching to a default theme to see if any are causing these issues?

Where did you get this theme from?

My Boss bought it from themeforest. It seems like thats where the problem lies. Deactivating plugins doesn’t do anything. But changing the theme works! Tried Twenty Twelve and it looks like it works 100%. So I’ll try chat with the Nexus theme guys and see if I can resolve this issue.

Ah found the problem! The Nexus themes compateability stopped at WordPress 3.5! So the only way for me to keep my sites displaying as they should is to downgrade!There an easy way to do that?

Nope. Nor do we recommend downgrading as your site would be exposed to a very real risk of being hacked.

Thought your going to say that.Thankx.