Please Help! Site Front End Not Loading

Some time during Sunday night/Monday morning the front end of my site has suddenly and unexpectedly become unavailable. Typing in the URL for the home page yields a blank page. Clicking on any search result from a search engine also results in a blank page.

Where do I start trying to figure out what is wrong? I have changed nothing on the site in the last few days and certainly not over the weekend.

I have tried clearing the cache, but that makes not difference.

Any help greatly appreciated.

Have you tried to disable some 3rd party addons?

Not yet. I'll try that. Thanks!

Working now…

I am using the VIVAshop theme and for some reason the licensing addon had turned itself off. Not sure why or how that would happen. But anyway, glad it was that simple.