What is causing blank pages?

[1993miatale]

I am running 4.2.1 for my forums, have been for some time. For ages and not terribly often but from time to time a thread could be a few pages long or many and out of nowhere a page will go blank, just a white screen. What is causing that?

[snakes1100]

Can be caused by a few different issues, did you check your sites error logs?

You can also enable display_errors in php.ini to help uncover the real issue.