I am having trouble updating Wordpress from the admin area. The update process crashes in pure random fashion. It says that file copy failed. I've added the lines to log source and destination paths, but it's not getting clear:
[21-Nov-2014 07:23:50 UTC] Source: D:/WEBROOT/domain.com/www/wp-content/upgrade/wordpress-4.tmp/wordpress/wp-admin/includes/image.php
[21-Nov-2014 07:23:50 UTC] Dest: D:/WEBROOT/domain.com/www/wp-admin/includes/image.php
[21-Nov-2014 07:23:50 UTC] PHP Warning: copy(D:/WEBROOT/domain.com/www/wp-admin/includes/image.php): failed to open stream: Invalid argument in D:\WEBROOT\domain.com\www\wp-admin\includes\class-wp-filesystem-direct.php on line 219
... And suddenly, a few tries later ...
[21-Nov-2014 07:26:41 UTC] Source: D:/WEBROOT/domain.com/www/wp-content/upgrade/wordpress-4.tmp/wordpress/wp-admin/includes/image.php
[21-Nov-2014 07:26:41 UTC] Dest: D:/WEBROOT/domain.com/www/wp-admin/includes/image.php
No error, upgrade succeeded
That's a little confusing. The Web server user has been granted full control privileges prior to upgrade.
The OS is Windows Server 2012, the old Wordpress version is 4.0, the new version is 4.0.1. PHP version is 5.5