Error after update from 3.3 to 3.6.4

Trying to update a site from evolve 3.3 to 3.6.4…. it worked fine on the staging server for the site (same VPS / host settings as the live server), but after I update on the live site, the following error occurs and takes my site down:

Fatal error: Cannot redeclare class evolve_ThemeFrameworkMetaboxes in /home/strongproudready/public_html/missionready/wp-content/themes/evolve/library/views/metaboxes/metaboxes.php on line 3

I’ve re-installed the new Evolve manually in case the WP update was a problem, but that made no difference….

The staging server and live server site config and setup is identical, so I don’t see why this error should occur!

Thanks in advance for assistance…