BuddyPress.org

Hi!

In my Plugin BuddyPress-Emails at the backend there are 2 php errors for the e-mail sample. Could you please help me with this problem?
Error-Screenshot: http://666kb.com/i/dh3uoz52p92h4a7xr.jpg
I already repaired BuddyPress and re installed it but this doesn’t work.
Link: https://www.flotter-feger.at

Thank You!

Error 1:
Warning: Invalid argument supplied for foreach() in /www/htdocs/XXXXXXX/wordpress/wp-includes/class-wp-list-util.php on line 153

147 public function pluck( $field, $index_key = null ) {
148		if ( ! $index_key ) {
149			/*
150			 * This is simple. Could at some point wrap array_column()
151			 * if we knew we had an array of arrays.
152			 */
153			foreach ( $this->output as $key => $value ) {
154				if ( is_object( $value ) ) {
155					$this->output[ $key ] = $value->$field;
156				} else {
157					$this->output[ $key ] = $value[ $field ];
158				}
159			}
160			return $this->output;
161		}

Error 2:
Warning: imploded(): Invalid arguments passed in /www/htdocs/XXXXXXX/wordpress/wp-content/plugins/buddypress/bp-core/classes/class-bp-admin.php on line 1011

1009		// Output each situation as a list item.
1010		echo '<ul><li>';
1011		echo implode( '</li><li>', $situations );
1012		echo '</li></ul>';
1013	}

Serverconfiguration:
PHP-Version 5.6.29-nmm1 (64bit)
MySQL-Version 5.5.52-nmm1-log

WordPress-Version 4.7.2
BuddyPress Version 2.8.1

Themes: DIVI + Child-Themes

installed Plugins:
bbpress-notify-nospam Version 1.15.4
bbp-private-groups Version 3.4.1
bbpress Version 2.5.12
buddypress Version 2.8.1
gd-bbpress-tools Version 1.9
wp-monalisa Version 3.9
ultimate-member Version 1.3.83
tinymce-advanced Version 4.4.3
contact-form-7 Version 4.6.1
flamingo Version 1.5
anything-order Version 1.0.3
rocket-maintenance-mode Version 3.7.3
backwpup Version 3.3.6
akismet Version 3.3
elegant-themes-updater-master Version 1.2
custom-404-pro Version 2.0.2
printfriendly Version 3.7.3
user-role-editor Version 4.31.1