If you have the same type of error, probably you have the offending plugin plugins or groups and recommend deactivating all plugins for the upgrade. You can also try what I did and see what plugin is causing the problem. Keep in mind, only the most recent plugin disabled, but a combination of two or more modules.

Another solution, which I try, but others have found success with WordPress increasing memory limit. To increase the memory limit, add this piece of code in wp-config.php file immediately after the opening php statement:

define ( ‘WP_MEMORY_LIMIT’,'64M ‘);

If you do not know how to edit the core WordPress file, sorry I will not in this message, and I suggest you stick to switch off the solution or more plugins, see this issue in the WordPress.org forums.