1 I disabled all WordPress plugins (not very graceful) by renaming the “plugins” folder in wp-content to “~plugins”
2 going back to the plugin area in the wp-admin give the message that all your plugins are gone, and therfore deactivated
3 I renamed my plugin folder ‘~plugins’ back to ‘plugins’ and all my plugins showed up in my admin again, deactivated.
4 Activating them one by one gave me a 500 error again by activating “Group E-mail Subscription” http://wordpress.org/extend/plugins/buddypress-group-email-subscription/
5 repating the proces, but skipping the “Group E-mail Subscription” gave me a up-to-date BP, I have to find a other solution to email my groups… (any ideas?)