Solving debugging errors of Live Stream Widget

Hi,

I’m trying to debug my WP install and have several errors with the Live Stream Widget. I got 4 error messages, but they seem to be all caused by the same issue.

Thank you in advance if you could help me to solve these errors below:

Strict Standards: Declaration of Walker_Live_Stream_Checklist::start_lvl() should be compatible with Walker::start_lvl(&$output, $depth = 0, $args = Array) in /Applications/MAMP/htdocs/sxtest/wp-content/plugins/live-stream-widget/live-stream.php on line 677

Strict Standards: Declaration of Walker_Live_Stream_Checklist::end_lvl() should be compatible with Walker::end_lvl(&$output, $depth = 0, $args = Array) in /Applications/MAMP/htdocs/sxtest/wp-content/plugins/live-stream-widget/live-stream.php on line 677

Strict Standards: Declaration of Walker_Live_Stream_Checklist::start_el() should be compatible with Walker::start_el(&$output, $object, $depth = 0, $args = Array, $current_object_id = 0) in /Applications/MAMP/htdocs/sxtest/wp-content/plugins/live-stream-widget/live-stream.php on line 677

Strict Standards: Declaration of Walker_Live_Stream_Checklist::end_el() should be compatible with Walker::end_el(&$output, $object, $depth = 0, $args = Array) in /Applications/MAMP/htdocs/sxtest/wp-content/plugins/live-stream-widget/live-stream.php on line 677