I've had this error come up and the solution for me has been with permissions.
It looks like if the /themes/default/cache folder is not writable by the webserver, then you get this error.
In my situation I am unable to set the group to one which includes the webserver, so my only option is setting perms to 777. The other issue with this is, any time I upload files to my server, I have to reset the permissions as the server sets them to 775 automatically.
But it works, and that's a good thing.
Hope this helps,
-peel
It looks like if the /themes/default/cache folder is not writable by the webserver, then you get this error.
In my situation I am unable to set the group to one which includes the webserver, so my only option is setting perms to 777. The other issue with this is, any time I upload files to my server, I have to reset the permissions as the server sets them to 775 automatically.
But it works, and that's a good thing.
Hope this helps,
-peel