Hi,
From the error message it looks like that the new PHP handler has no permissions to the file system (or parts of it). It is not clear from the message which directory is at fault exactly, but it should be somewhere around the wp-content folder.
Make sure that the server apache user has permissions to write to directories, it is very important for WordPress to run properly. Usually checking the file permissions on the “wp-content”, “wp-content/uploads” and “wp-content/cache” folders does the trick.
If you are using php-fpm check if the user and group is correctly set for the pool. Otherwise PHP will have no write permissions for the folders.