i tried to upgrade my 1.8 installation to latest magento version by connect.
after upgrade my backend login ended in a white page. i read HERE that maybe a folder is missing and downloaded latest magento to copy the missing folder manual. Nothing happend so i decided to copy all folders in default/default.
I got a error warning from windows that some files can't get replaced because there are folders named like this files ... ?
What happend and what did i do wrong while upgrading? is there a special order to upgrade magento core packages?
Please check below link to resolve your problem.