It's quite hard to understand where and if there's a problem by just these few informations.
Would be better, when happens again, if you could turn on the PHP errors so that we know what's going on.
Note that usually a blank page means there's some PHP issue blocking the page from loading but without the errors showing up, it will just be a blank page and not much we can do about it.
If you mean the, Debug Sistema, dont give me nothings in the front page, only white page the same,no error.
If you mean somethings else let me know i will do it.
To see the php errors, you will need to edit your php.ini file on your server. Change the "display_errors" to On. (remember to turn it back off when finished)