This happens usually results into just a plain white screen with no error message which makes it the most annoying and puzzling because you have no clue where to look and what to fix. (fastest way to check here, check your internet connection and(or) maybe refresh your browser for a couple of times.)
Okay now, most of the time it is caused when a script exhausts PHP memory limit. It can also happen due to a configuration on the server. It is also possible that a user would only see white screen of death on certain sections of their site. If you’re running your website for sometime now, try to recall the last few things you did to your website (eg. uploaded and activated a new theme, plugin or etc.)
Things to do
1) Deactivate the last few themes or plugins that you have installed. (then refresh the page that you saw the white screen, most of the time, it is cause by these.
2) Not so sure which plugins? Well, you can choose to deactivate all plugins, then enable the plugin one at a time, to be sure which plugin is causing this.
3) Replace it with the default theme, but remember to back up your theme folder first. After the back up, delete the theme that you have installed (or using currently) and reinstall the theme. WordPress will automatically fall back to the default theme (eg. twenty thirteen) when you delete the current theme.
4) Increasing the memory limit. The white screen occurs usually when your memory is exhausted. Increase to a higher limit like 64M to 128M. This might help but it’s also dependent on the hosting provider.
5) Your caching plugin. This might be the cause as well. Just empty your cache and refresh your website. If it works, then you should delete the plugin and install a better one.
6) You can try to use the WordPress debug function.
Just open wp-config.php and add
error_reporting(E_ALL); ini_set(‘display_errors’, 1);
define( ‘WP_DEBUG’, true);
Once you add this, go to the blank screen and click refresh. It will now have errors, warnings, and notices. These may be able to help you determine the root cause.
What can you do if you discover that a particular plugins or themes that causes the problem?
1) Most theme and plugin providers have good documentation on what they are selling or providing. Just make sure you read them thoroughly.
2) After that, just email your respective theme or plugin providers and explain it to them concisely, and wait for their reply.