MarketPress 2.8 Session Issue - No Such File

I notice an error caused by a php message that appears at the top:

Warning: session_start() [function.session-start]: open(/var/chroot/home/content/83/2832183/tmp/sess_nd4qlhvtkb5qpcp55jagog6617, O_RDWR) failed: No such file or directory (2) in /home/content/83/2832183/html/wp-content/plugins/marketpress/marketpress.php on line 882

What does this mean?

Love MarketPress BTW! Thanks for the help.