Device or Resource Busy
An attempt to access or modify something failed as it is already in use. Probably the most common reason for seeing this is trying to unmount a disk partition while processes have open file descriptors on that device.
lib/main.php:944: Notice: PageInfo: Cannot find action page
lib/main.php:839: Notice: PageInfo: Unknown action
lib/plugin/WlugLicense.php:99: Warning: Invalid argument supplied for foreach()