I just found a way to fix this problem.
here's what i've done
for the file:/libraries/joomla/cache/storage/cachelite.php
open it and look for "funcion test()"
it's normally at the bottom
find it and remove the word "static" in the same line
if there's still problems with
/libraries/joomla/cache/storage/wincache.php
/libraries/joomla/session/storage/wincache.php
do the similar thing to them
