修复wordpress安装buddypress插件后的警告

周末有空下了wordpress和buddypress，安装并激活buddypress后，出现一长串警告

( ! ) Warning: Creating default object from empty value in \wordpress\wp-content\plugins\buddypress\bp-loader.php on line 71
Call Stack
#    Time    Memory    Function    Location
1    0.0013    140680    {main}( )    ..\index.php:0
2    0.0021    142808    require( '\wordpress\wp-blog-header.php' )    ..\index.php:17
3    0.0031    152936    require_once( '\wordpress\wp-load.php' )    ..\wp-blog-header.php:12
4    0.0046    160336    require_once( '\wordpress\wp-config.php' )    ..\wp-load.php:29
5    0.0074    217240    require_once( '\wordpress\wp-settings.php' )    ..\wp-config.php:90

6    0.4971    8465680    include_once( '\wordpress\wp-content\plugins\buddypress\bp-loader.php' )    ..\wp-settings.php:198 

   这个错误一般是php的版本不同造成的，使用php5.3后就没有这个问题了