About: John Neilson

I just had a similar error and got it fixed by going to my hosts Cpanel.
Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 122880 bytes) in /home/neilsons/public_html/blog/wp-content/plugins/s2member/includes/classes/menu-pages.inc.php on line 704
when I tried to add the jet pack; now I cant login or view my blog
http://neilsonsweb.com/blog
I went in to my hosts server side Cpanel and in the file manager tried renaming the file and was able to login
but then received these errors

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘c_ws_plugin__s2member_menu_pages::add_admin_options’ was given in /home/neilsons/public_html/blog/wp-includes/plugin.php on line 406

Warning: session_start() [function.session-start]: Cannot send session cookie – headers already sent by (output started at /home/neilsons/public_html/blog/wp-includes/plugin.php:406) in /home/neilsons/public_html/blog/wp-content/plugins/associate_goliath/associate_goliath.php on line 377

Warning: session_start() [function.session-start]: Cannot send session cache limiter – headers already sent (output started at /home/neilsons/public_html/blog/wp-includes/plugin.php:406) in /home/neilsons/public_html/blog/wp-content/plugins/associate_goliath/associate_goliath.php on line 377

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘c_ws_plugin__s2member_menu_pages::log_file_downloader’ was given in /home/neilsons/public_html/blog/wp-includes/plugin.php on line 406

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘c_ws_plugin__s2member_menu_pages::logs_zip_downloader’ was given in /home/neilsons/public_html/blog/wp-includes/plugin.php on line 406

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘c_ws_plugin__s2member_menu_pages::add_admin_styles’ was given in /home/neilsons/public_html/blog/wp-includes/plugin.php on line 406

Warning: call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, ‘c_ws_plugin__s2member_menu_pages::add_admin_scripts’ was given in /home/neilsons/public_html/blog/wp-includes/plugin.php on line 406

In my case I was able to identify the plugins giving the errors… azon profit poster and another plugin called associate Goliath… two plugins having issue because of updates to clickbank and amazon..deactivated , notified the developer and now back to normal.
How this helps but it appears that your using multi site; (http://premium.wpmudev.org/manuals/wpmu-manual-2/using-mu-plugins/) and I dont know anything about the theme or its plugins but Im posting anyway to give you an idea of where to start ….

Perhaps you could do the same .. go in from the cpanel manager side from your host and remove the plugin restore the site and go from there…
Cheers
John N