blank admin page after ceon 4.4.1 install

Hi.

After I installed the CEON URI 4.4.1 my admin page is blank.

Not quite sure how to fix this. My store site is fine when accessed from brower however I can't log in to the admin page. It is blank now. I get a HTTP500 error and in the debug file I found this.

PHP Fatal error: require() [<a href='function.require'>function.require</a>]: Failed opening required 'includes/functions/sessions.php' (include_path='.:/usr/lib64/php:/usr/lib/php:/usr/share/pear') in /home2/(my Cpanel Login user name here)/public_html/zcadmin/includes/init_includes/overrides/init_sessions.php on line 28

Line 28 is

require(DIR_WS_FUNCTIONS . 'sessions.php');

The page loads but does not finish loading. I get the blank page with no login boxes showing.

Any help would be appreciated. I've never done much htaccess rewrites except basic copy paste stuff so consider me a newbie on that please. Thanks so much for any help. I'm sure I'm not the only one this has happened to.
CEON version is 4.4.1

Sylvia