MODx Parse Error

Hey All - I have just noticed that all my templates have an error message suddenly.

MODx encountered the following error while attempting to parse the requested resource:
« PHP Parse Error »

PHP error debug
Error: Unknown: open(/var/php_sessions/sess_1b266028b140ce59bef55f354f5fb310, O_RDWR) failed: No such file or directory (2)
Error type/ Nr.: Warning - 2
File: Unknown
Line: 0

Parser timing
MySQL: 0.0039 s (0 Requests)
PHP: 0.2947 s
Total: 0.2986 s

Anyone have any idea how one might get this error msg?

www.yellowstonesummerproject.com

Has your hosting company made any changes to the server recently? It looks like something has happened to the default PHP session file location.