I'm thinking that an older version was released to patch some PHP5 errors, but I'm not for certain which version it was introduced. 7.1.1 is pretty ancient...
But, if it worked before, I'd go through and check permissions on the cache and templates/compile directory; both should be 777 and then delete the files within them (and possibly run the "Clear Cache" script from the control panel.
Last edited by Gizmo; 11/05/2010 1:07 PM.