I have been using W3 Total Cache for the past 2 months without any issue until scheduled tasks (such as posts and backups) stopped working 2 days ago.
I used an error log plugin (Error Log Dashboard Widget) to figure out the culprit. The following error was found recorded in the error log.
PHP Fatal error: Call to undefined function w3tc_button_link() in /home/virtudwt/public_html/wp-content/plugins/w3-total-cache/lib/W3/GenericAdminEnvironment.php on line 99)
In summary I navigated to the CDN section of W3TC and unchecked the option "Don't replace URLs for following user roles". After which the scheduled tasks began to function again. I re-enabled the above option and checked "Administrator" The problem returned.
I really want W3TC to prevent requests to the CDN for logged in users. Any help in regard to solving this problem will be much appreciated.