Hello, I think posting a solution here is a good idea. So:
Relpace this line
file core-patcher.php
line 273
$cSet = str_replace('$wp->init()', 'function wpu_deferred_wp_load() { $GLOBALS[\'wp\']->init()', $cSet);
with this
$cSet = str_replace('$GLOBALS[\'wp\']->init()', 'function wpu_deferred_wp_load() { $GLOBALS[\'wp\']->init()', $cSet);
and
Don’t forget to empty all the files (other than .htaccess and cache_readme.txt) from the /wp-content/plugins/wp-united/cache folder – otherwise you’ll still get the white screen of death on your forum. (by ConfusedTA)
Good luck!