[@uvo Participant 10 years, 7 months ago]

Changing the remove-action solved the problem:

add_action(
  'bp_groupblog_create_screen_markup',
  function() {
      remove_action( current_filter(), 'bp_groupblog_signup_blog' );
  },
  9
);

Found the solution here.

[@uvo Participant 10 years, 7 months ago]

I didn’t found a solution for this problem yet. I have maybe tried hundreds of variations but nothing works yet. Can anybody point me in the right direction?

[@uvo Participant 10 years, 7 months ago]

You are right. “has_action” returns false at the time of the remove_action. Unfortunately bp_include did not help. I checked the action-hooklist (http://goo.gl/C5exli) bud i can’t figure out, which hook is the right one.
If I replace the action in the bp-groupblog-classes.php (create_screnn() & edit_screen()) where the original function is hooked and excecutet (do_action) the output is correct. Bud I don’t want to edit the original class.
Is there a way to overwrite the plugin class or is my first approach the better way and if yes, how can i find the correct hook?

Thanks.