Blank Page URGENT
What did you change before it stopped working?
Check if your theme files are in place via FTP, some FTP clients can have strange behaviour and move a file when you wanted to do something else. Check if the index.php is in place and if .htaccess is unchanged if you had it. Did you activate pretty urls?
Ok, so after looking around i think:
1. Your database-connection works (Login page displays, your register settings seem to apply)
2. It must be something more than your theme-folder. I think if it was theme-related, you would see the html output without any styling.
3. I am very sure it is either the .htaccess or the index.php in the root of your folder that is causing this failure.
No idea how this i happening, but first step is resolving the emergency = get the site up. Do you have FTP access to see if those files are in place?
First step, submit a support ticket. Maybe they can see something that you cannot.
Second step, login to your cPanel Interface and find the FileManager or however the thing that lets you view your file system is called. navigate to the root of your site (should be inside public_html), where there should be all the folders of c5 (/blocks, /concrete, /config...) in this directory, there should be a "index.php" file. is it there?
There should also be a .htaccess file that could be faded grey.
Can you log into your dashboard? If so, go check if pretty urls are activated (system&settings->pretty urls) to make them work, you need a .htaccess with the right content. Have you maybe tried activating PrettyUrls? Could be that bluehost does not allow it.
This happened to me the first time installing with simple scripts because it wants to put it in its own folder but doesn't tell the server(bluehost) to point to the new folder
php limits of the page are usually because you are exceeding your set php memory limit for a page (such as to-many photos or incorrectly compressed files taking to much load time)
you can try to fix this by changing your php.ini file to 128mb
I have had issues with some files being to big and i fixed the problem by changing the page version from the sitemap to an older one that had less stuff on it
Normally when I have seen this, it is the result of a misbehaving add-on or an error in the config file.
[28-Jan-2014 12:37:47 America/Denver] PHP Parse error: syntax error, unexpected ''concrete18.104.22.168_updater);?>' (T_ENCAPSED_AND_WHITESPACE) in /home2/liveunit/public_html/Main/config/site.php on line 6